I no longer have much difficulty making and breaking habits. I also have ADHD, and have not always been so able. Here is much of what I've learned from asking questions like yours for the last 20 years:

1. It helps to be as meta-cognitive as possible. I am still learning to examine the thoughts and impulses as they appear. This is an ongoing process that, to the best of my understanding, has no discrete endpoint. I use a formal-ish (but consistent) daily meditation practice to keep the meta-cognitive pathways strong, and I practice as often as I remember to. My go-to "in the wild" practice is a quick mind-body scan: how is everything right in this Now? I find it beneficial in those moments to invite areas of (mental and physical) tension to relax a bit. It makes me feel better, so I want to do it more.

The primary benefit in this context is that you will begin to see the excuses and outright lies that the mind invents to get out of doing things it anticipates might be like work. Brains are lazy creatures! You have the choice to believe, disbelieve, and act on thoughts or not; but only if you are aware of what they are (and what they are not) in the first place. This is nowhere near as trivial as it sounds! And it can only be accomplished by routine examination of the mind.

2. Build systems and procedures that cause things to get completely done every time. I'm a big fan of checklists! Many of these live in my head, but there must be some kind of somatic component to the act of going through the list*. Paper and pen(cil) work well here. Checklists may not be for you! Try stuff until something feels good, then try to go with it. If some part of a system feels like a chore, throw that part out. If that breaks the system, throw out the whole thing and try something else.

• Example: On my way out of work I put my bag in the car and say "Bag", my lunchbox "Box", and my hard hat "Bucket" (alliteration, yo!). Then I check my pockets for things it would be easy to take home but I shouldn't. Each of these things has a dedicated location on my person where I will find it if I still have it. I name each thing: "Keys, computers" and touch where each belongs. Too many times I've saved an hour of driving this way!

3. Export the leading ends of procedures to the environment. Related to TAPs, this practice gives me a concrete, visible, tangible place to start every single time. I build daily routines around interactions with my partner and family**. My work routine is contained in a checklist on my phone (that I made more amusing by writing it in a phonetic alphabet, coloring it brightly, and structuring it in three acts, all so I would want to look at it a little bit more. YMMV).

** Example: My evening routine is maintained between me and my partner. We brush teeth and the cat, dress for bed, sit a short meditation, and maintain hair together in that order every day. It's actually kind of disturbing when circumstances cause us to sleep in different locations for a night! But that occasional discomfort is well worth it so I remember to floss nearly all the time!!

4. Don't be afraid to fail. Popular methods like "Don't Break the Chain" suggest that habits are an all-or-nothing proposition. But the truth is that with that kind of attitude, a single "miss" can generate a sense of failure that breaks the habit entirely! Nearly all of our "daily" habits can be accomplished "daily-ish" without losing much utility. The important thing is to go back to doing the thing on the next opportunity. When you notice you've drifted, that's a win! It's a chance to get back on track doing something you've decided is good for you.

Too, starting a new habit is an extremely personal thing! Anybody who says they have all the answers and can transform your life if only you try their system is trying to sell you something. Use new systems on a trial basis, the duration of which you should consider ahead of time. During that probationary period, get to know the system and all its parts. What doesn't work for you should be thrown out to reduce the friction of using the system. Sometimes it's by discarding something that we learn its value, and in this case you can just undelete with impunity.

5. If the a system or habit stores any kind of data (e.g. note-taking, journaling, &c.), don't worry about porting everything from the old system. That will just create more start-up friction and make the new thing feel like a chore. Bring over old stuff only as you need to!

I'm similar and haven't found anything that works well. Reading how most EAs talk about their self-improvement "life hacks" always makes me think "fuck you, lol." I constantly alternate between periods where I'm trying lots of good routines at once and I'm somewhat productive and periods where things fell apart and I'm unproductive. In my experience, most of the leverage to be gained is by trying  to reduce the difference between these two states by not punishing myself for falling off the wave, i.e. getting right back into the attempts after a bad day or five. And if I'm on the wave I try to be extra cautious about avoiding things that could derail me.

I took time off from work late last year for personal reasons and used the opportunity to start some deeper-reaching attempts at mindset improvement based on CBT, visualizing my ideal day, and so on. I'm about to start schema therapy. Ideally I'd do the exercises daily but that's already challenging for obvious reasons. I haven't noticed any productivity improvements so far but I'm at least feeling better about myself.

Tell the people who tell you, you aren't trying hard enough to take a hike. They are useless in this situation, well-meaning but useless. Not everyone with ADHD or other executive function disorders struggle with this to the full extent of no habits. I explained to one person...you have auto pilot, you do the same thing over and over and you reach a point where you don't even have to think about it anymore. I have test pilot...if it isn't new, exciting or death defying I won't even show up at the airport. If I do something the same 21+ days in a row it actually becomes more difficult for me not less. Because my brain is actually working against me. And the number of people on this planet that understand that, are miniscule at best. You don't have habits. They are very common and very helpful but you can still do great things without them. What you have to do is leverage what you do have...you have preferences, you have an environment, you have interaction with others, you have choices. I have had counselors tell me that not having habits was impossible. Most of what I thought were habits growing up was just me interacting with structure and consequences other people had put in place. My preference was for their acceptance and approval so I did things the way they wanted but it was never routine for me. There was always a high level of risk involved in anything I kept going for any length of time. When the risk was gone so was the behavior offer without me even really noticing it had changed. Now I don't even use the word habit. I say strategy and I change strategies often to get the results I want. I don't waste time feeling bad about strategies that no longer serve me or feeling like failed because I couldn't force it to work for me. I pay attention to my energy and effort, how much I am expending to get my needs met. I have simplified my life and possessions to make it easier for me. I have support from people who love me, who help from time to time. I recognize that I have limits and I live the best life I can within them. You can do amazing things without habits, you really can!

Are you relying on willpower? I’ve found it useful to see myself as a dumb robot that responds instinctively to its environment, and focus on data driven behavioral interventions instead of personal decisions. For example, instead of “committing to spend less time on Facebook”, I got a chrome extension that makes me wait 30 seconds before o can access Facebook. Instead of trying to will myself to brush my teeth every night (which wasn’t very effective), I kept a bottle of gummy vitamins in my bathroom and I got to eat one if I brushed my teeth after. To get myself to do work, I put up my daily pomodoroS on a board my housemates could see. These feel stupid, but worked much better than any personal goals I ever set.

I also realized that working on my depression made the small stuff come more easily. That may not be your situation though.

I felt like this for a long time, turns out it was mostly a depression issue. So therapy and meds helped a lot. Also, there are executive functioning coaches who work with exactly these types of problems.

another thing that helped was setting my environment up in a way that will trigger me to act like I want. blocking distracting websites, putting red lights in my bathroom so I can't pick my skin, putting a book I want to read on my desk, putting my sneakers and elliptical where I will walk past them often.

also, meta habits. there are small mental tweaks that will help you function better as a whole, one of them is "microsteps". if there's a task you want to do and you're not doing it, it's probably because you're overwhelmed. to fix this, figure out the absolute smallest step needed to begin the thing. So if my task is to make dinner and I'm stuck on the sofa, I think "okay- put your feet on the floor. now stand up" etc. after 1 or two steps I go into autopilot and can do the thing.

Hey Masasin,

I have ADHD, had been medicated the better part of 15+ years (no longer now) and although it's taken a tremendous amount of work and bouncing off the train and getting back on I have been able to build a 'productivity' system where I use routines to enable habits (like brushing my teeth 2x a day). It was not easy but it was necessary. I didn't want to be a complete f'n mess all day everyday and I knew that my ADHD energy could be corralled into something of a positive force and that's where I am today. I know you think you can't do it today but I assure you, you can. It f'n hard but you can. I go to bed on time, I wake up 5:30am everyday, I get shit done, I am excelling at work, and best of all the habits are sticking and producing everything I hoped they would. All the best! 

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