How do you apply schematic thinking to one's own chess games? I can never figure out how to come out with many micro plans in an endgame. I'm not sure in which order they should be applied as well. How do you apply schematic thinking to one's own endgames?
There is an excellent book by GM Jonathan Hawkins called "Amateur to IM" which deals with this. There are a number of stages you need to go through.

First of all when looking at a mini plan you need to consider a) will it work, or can my opponent easily stop it and b) if it does work will it actually do what I want it to do - give me a winning position, say.

So, for instance, if you can force an exchange into a BPKvK endgame you might think you have an easy win, but if the pawn is a rook's pawn on the wrong side of the board then you will be disappointed. You can only know the mini plan was a bad one if you can properly evaluate the final position. 

Hawkins aims to do two things in the book. First to help you to think the right way about endgame positions so that you evaluate mini plans and quickly eliminate those that aren't going to do the job and not waste any more time on them. Second to help you build the knowledge of endgame structures that will enable you to correctly evaluate the final positions of your mini plans.

Hawkins points out that the big advantage that stronger players have in the endgame is not their ability to calculate much longer variations much quicker (generally speaking they don't have this!) but their ability to quickly and correctly evaluate candidate positions that they are aiming for. They are not high speed calculators. They are very good evaluators who don't waste time calculating mini plans which they know in advance are not going to work, so saving time and making it look like they are high speed calculators!