I am looking at creating a binder of all the practice problems that I do. I was thinking about copying the problem and solution together on a page and then organizing them by problem type. Has anyone done this? It seems like it would take a lot of time to do but would be very helpful.
Haha! Yes. The great debate. 'is it worth the time'? I obviously think 'yes'...since this is basically ALL I did, and I passed using that binder I made. It does come down to 'learning style' - I tune out of lectures unless I'm writing something down, so the 'binder' method worked well for me because all of my studying also involved writing things down (mostly working out solutions).
My 'method' is
laid out here. I wrote it as a 'step by step' (week by week), but in the end your summary in your question essentially covers the gist of it. I was rigorous about the 'weeks' at the time because I only had 9 of them left to study when I signed up.
Unsolicited advice;
If you are taking the time to write out solutions, make sure to actually
take the time. i.e. write out the solution in full (all steps, all formulas used in their native form before inserting numbers). If the problem you are trying to solve is only similar, but not identical, to your reference solution, having all the steps/formulas written out helps you 'adapt' the process as needed for the slightly different problem type. As a counter-example - the 'solutions' in the NCEES practice exam book are about as useless as a chocolate teapot - so many steps are skipped and you really have to already know most of the solution in order to follow their 'worked' solutions.
Also, if you got the problem wrong originally, note in the 'correct solution' page somewhere what you did wrong (especially if it was an easy mix-up or mistake to make again). 'Present you' understands what you did wrong, 'future you' may just repeat the mistake unless there's a kick-in-the butt to remind you not to mess it up again. Like, I literally highlighted the 'square root' symbol in one formula and pointed at it with an arrow and wrote 'hey dummy, don't forget to take the square root at the end'.
Also, if the problem is qualitative, write out WHY each of the WRONG answers was wrong. They are usually 'close' or 'half true' or some other tricksie thing, so writing 'option A is wrong because ___, option B is wrong because ___, etc' can really make that 'solution' more broadly useful in the future if a similar topic comes up. Also, some jot notes about why the RIGHT answer is right, and titles/page numbers to your favorite resource-book sections on the topic. TLDR: if you are going to take the time to write out page-by-page problem/solution sets, make each one as useful as possible to 'future you'.