Reposting my advice from /kind/. Remember, I'm not any professional but those ideas seem to work for me. Take everything I say with a grain of salt.
Forget your goal.
Yes, I'm serious about that. I know that you definitely have some goal in mind when you're trying to self improve, but it's necessary only to begin the process. Later on, it actually might be harming to you. If you constantly keep reminding yourself of your goal, you will become impatient. Visualising yourself completing the goal, or keeping your goal in mind makes you want to accomplish it in this very second, so you're less likely to work for it. I think that a better way to view self-improvement is doing things you're supposed to do as something completely normal like eating breakfast or brushing your teeth.
For example: You start exercising to get less fat, but after you begin doing it, you should forget about that and try to exercise everyday without thinking about it. I prefer to think about a workout just as a part of my schedule, or something I do because I want to, not something that I do to accomplish some specific goal. If you view it as a part of your normal routine, it will eventually become a habit.
>Don't rely on motivation
No, don't do it. Motivation makes you feel better about the things you do, but only a short amount of time. It's an emotion, it will fade away after some time. You won't feel it everyday.
Instead, try to train your self-control. Your motivation might make things easier for you, but it won't help you in the long run. By training self-control, it will be YOU who will learn to take care of hard tasks easier. And the best part? If you train your self-control, not only will you be able to get better at the subject you're training, but it will be far easier for you to pick up, and get better at other things a well.
>Keep a schedule
Remember to work with some kind of a schedule, but try to make it so that it will be easy for you to start doing, whatever you want to do. If you're a NEET, or have a lot of free times, you should probably start right away when you wake up, if you're still in school, starting right after school is also a good idea, if you're working, start after work.
>Don't push yourself too hard, try to start with smaller tasks, but do them everyday.
It will be hard for you to take do harder feats at the start. Instead of learning for two hours every day, try learning for only a half, but be sure to do it. After some time, you will be able to carry on with the harder stuff.
>Don't let anything break your schedule.
If you stop with your routine for one day, it might be hard for you to get back in it the next day. Keep that in mind.
>If you want to exercise, check your health first.
I'm serious, that can make you break your routine very easily.
>Don't give yourself strict time constraints.
They are hard to follow, especially at first. Think in lines of "morning", "afternoon", "evening" and set your schedule according to that.
>Be prepared to fail
You are not likely to succeed at first, self-improvement is hard work! You will definitely make mistakes, get bored, tired and unable to go further. BUT
>Most importantly, never give up.
You might fail, you won't succeed at first, but every time you do, you will become slightly stronger. You will be able to control yourself better, and the next try might go further than before. Withstanding even a few days, and then coming back for more is a feat in itself! You should be proud of even the fact that you tried again don't get the pride get to you too much though, if you do you'll stop trying. It's better to fail and then try again, than to succeed and never build upon that success.
I would wish you good luck in improving, but you don't need it. You're perfectly capable of doing this on your own. Believe in yourself anon!