I would recommend to only focus on the object-level problem you're trying to solve.
For example:
In mathematics, notation is basically a solution to the small working memory that we have, you just have to find the analogue for whatever you're trying to solve. I doubt something will permanently fix low working memory in the long-term (e.g. dual n back) you can of course try some acetylcholine release agents or reuptake inhibitors which will make you more vigilant (e.g. the mildest one being coffee.) There's also some evidence pointing to fasting, sleep deprivation, niche nutritional protocols such as carnivore diets (or rather, strict exclusion diets where you remove some foods progressively until you find the one that does not suit you.)
Can confirm about the use of notation. Then it becomes learning/interpreting it (including in different contexts).
Something not directly about working memory, but which I found unusually helpful in the realm of "low-level yet very general learning strats", is the advice here: https://terrytao.wordpress.com/advice-on-writing-papers/on-compilation-errors-in-mathematical-reading-and-how-to-resolve-them/
Connect a stack style memory register to a pair of peripheral neurons, so that the neurons can send three separable nerve signals (push one, push zero, pop) and receive two separable inputs from the machine (pop one, pop zero)
Leave it connected for an extended period of time so that neuroplasticity can adapt to having a sense organ that is a low metabolic cost, fast binary storage device, might be worth trying a lot of double n back so the body adapts to using the new organ, and as a bonus, you'll get quantitative proof if it works.
Congrats, you're a superintelligence.
If I remember correctly, something like this was done in a rat and measurably improved water maze performance.
writing things down: helpful, has time and depth costs, unclear how useful it is for learning new things
I benefited a lot from re-practicing my handwriting, so that I could take notes as I read the sequences for the first time (which you can only do once).
Taking notes via handwriting is absolutely necessary to learn new things. In school they taught us that we lose 50% if we don't take notes but we ignored that along with all the other lame propaganda that it was mixed in with, even though it's very, very true. Writing to paper is like a computer writing to memory instead of RAM.
And if you're in the habit of trying to think about things worth thinking about, then that means you'll tend to come across things worth writing down.
If exercising arm and core muscles strengthens the body, then exercising hand/wrist muscles (while practicing handwriting) strengthens the mind.
Hi, according to this research, it might not be possible to increase working memory, since the memory limit seems to be the same for birds, monkeys and humans, and in extension in all animals:
https://phys.org/news/2021-12-brain-capacity-humans-birds.html
The scientists found that birds and monkeys—despite their different brain architecture—share the same central mechanisms and limits of working memory.
"... the existing literature on the influence of dopamine enhancing agents on working memory provides reasonable support for the hypothesis that augmenting dopamine function can improve working memory."
—Pharmacological manipulation of human working memory, 2003
writing things down
A good idea but too general to be good advice.
More specifically (not an exhaustive list):
More generally, consider dumping your mental state to a written medium more often. You should probably have a way to do this on both your phone and computer that doesn't take too much thinking to summon up a text field that you can edit and then have the text get stored in an inbox or similar catch-all folder somewhere.
If you feel silly writing down trivial stuff, it's helpful to think "I want to remember all of it, not just most of it."
I do this currently, basically writing a stream-of-consciousness regarding whatever I'm doing, in a window right next to where I'm doing the actual writing/coding. Helps for context-loading, as you said, and also prioritization. Have barely begun applying this, but it's my new central default working method for most things.
Ideas so far:
As usual with my threads on this sort of topic, this is looking for wacky/anti-inductive/risky methods only.