The simplest question to attempt answering for the sake of producing an analysis is: "where are all the moments the evaluation changed?" -- and by evaluation I mean large changes like black is somewhat better changes to the position is just equal, or white is winning changes to white is slightly better.
I also like to check moments I was unsure or confused, and also any position I felt strongly about. If I felt like a move was definitely bad (or good), I want to check to verify that this is true.
How you do analysis can vary depending on what you're trying to accomplish, your rating, your time, etc...
If nothing else, I guess what I would recommend is to find 2 or 3 of the biggest mistakes you made. Categorize them (I could have checkmated but missed it, or my piece was pinned and that caused lots of problem, or anything else).
And then if one of them was a particularly bad mistake, choose it as the most instructive mistake of the game and save that position in some way. For example you could save it as a picture. Over time your "list of mistakes" will grow, and you'll be able to discover the weakest parts of your game by noticing recurring problems. Working on those problems is a fast way to improve your results.
So like many of you here I am trying to improve.
The steps that I am taking:
1 - Playing 2/3 games per day
2 - Learning - by watching videos and reading
3 - Completing puzzles
4 - Analysing my games
My question is - what the most effective way of analysing my games?
Is there a few simple questions that I should be looking to answer?