A good first message consists of "Compliment + be brutely honest and clear about what you want. Neither most men nor most women enjoy having a long small talk conversation via online chatting before meeting.

A good first message consists of "Compliment + honestly asking for what you want + greeting".

Don't ask the other person to be more vulnerable then you are but share vulnerability yourself when you ask the other person for something that makes them vulnerable.

A friend who makes money with dating coaching gave me that formula and told me that I should write messages that are more sexual. Given that there was no reason not to try, I did and was surprised about how positive the response were.

The quality of a dating profile is measured by how much emotional impact it has. The conveyed information is secondary. I personally go through the hero's journey on my profile in a way that shares vulnerability. You want a woman that reads your profile to feel something and that will make her interested to know more about you.

The "you should message me if" should be filled and filling it with relevant information makes it more likely that a woman will message you.

Photo quality matters a great deal for online dating. If you are very relaxed you look better. I personally made my last profile pictures after a hypnosis intervention but I guess you can get a similar effect with other ways of relaxing. Maybe a sauna or floating tank makes you relax well to look better immediately afterwards. Camera quality matters as well.

People are usually bad judges about the question of which photo presents them best. https://www.photofeeler.com is a website where you can get your photo's rated on presenting you smart, trustworthy and attractive. If you try different pictures and put in the work the resulting picture will make a better profile.