I think it would be good to put the points into subsections and then describe why each subsection is valuable. I have put some draft subsections below:

Have growth mindset

1. Nearly anything can be learnt or improved on. Aside from a few physical limits – i.e. being the best marathon runner is very difficult; but being a better marathon runner than you were yesterday is possible.

Clarify what X is

1. Make a list of what you think that X is. Break it down. Followed by what you know about X, and if possible what you think you are missing about X.
2. Do some research to confirm that your rough definition of X is actually correct. Confirm that what you know already is true, if not – replace that existing knowledge with true things about X. Do not jump into everything yet.
3. As you learn more about X, consider coming back to this point to confirm that these is still the original X, and not X2, or X3 etc.. (if you find you were actually looking for X2 or X3, go back over the early steps for Xn again.

Determine if it’s worth it to lean about X

1. Make sure your chosen X is aligned with your actual goals (are you doing it because you want to?). When you want to learn a thing; is X that thing? (Example: if you want to exercise; maybe skiing isn't the best way to do it. Or maybe it is because you live in a snow country)
2. Check that you want to learn X and that will be progress towards a goal (or is a terminal goal – i.e. learning to draw faces can be your terminal, or can help you to paint a person's portrait).
3. Get access to the best resources possible. Estimate how much resource they will take to go over (time, money) and confirm you are okay with those investments.

Determine best practices/common mistakes

1. Figure out what experts in the area know (by topic area name), try to find what strategies experts in the area use to go about improving themselves. (expert people are usually a pretty good way to find things out)
2. Find out what common mistakes are when learning X, and see if you can avoid them. (learn by other people's mistakes where possible as it can save time)
3. Check if someone is teaching about X. Chances are that someone is, and someone has listed what relevant things they teach about X. We live in the information age, its probably all out there. If it's not, reconsider if you are learning the right thing. (if no learning is out there it might be hard to master without trial and error the hard way)
4. Figure out the best resources on X. If this is taking too long; spend 10 minutes and then pick the best one so far. These can be books; people; wikipedia; website repositories; if X is actually safe – consider making a small investment and learn via trial and error. (i.e. frying an egg – the common mistakes probably won't kill you, you could invest in 50 eggs and try several methods to do it at little cost)
5. Consider writing to 5 experts and asking them for advice in X or in finding out about X.

While learning X, externalise what you have learnt.

1. Delve in; make notes as you go. If things change along the way, re-evaluate.
2. Write out the best things you needed to learn and publish them for others. (remembering you had foundations to go on – publish these as well)
3. Try to teach X to other people. You can be empowering their lives, and teaching is a great way to learn, also making friends in the area of X is very helpful to keep you on task and enjoying X.

Try to apply what you learnt and find ways to improve what you have learnt

1. try to find experiments you can conduct on yourself to confirm you are on the right track towards X. Or ways to measure yourself (measurement or testing is one of the most effective ways to learn)