My biggest roadblock with using Anki is figuring out what exactly is worth typing up into a card, when the material isn't just unrelated discrete items (i.e. vo

My biggest roadblock with using Anki is figuring out what exactly is worth typing up into a card, when the material isn't just unrelated discrete items (i.e. vocabulary) that don't stick easily. For example, in lectures I'm usually able to understand most of what is taught on that first exposure, but of course I don't have everything committed to long term memory right away. So, sometimes I'm tempted to write a lot of things down or type them up in Anki (which can get quite tedious). However, in math for instance, you pretty much have to know the exact definitions of theorems to apply them in proofs. Thus you refer back to the textbook or lecture notes/video (if available) when applying a theorem in a problem, and soon you have that definition down cold in memory. Similarly, in courses or subjects where you need to do a lot of problem solving or application, you can look back at source material for concepts or definitions as needed (this itself is probably a form of spaced repetition). In cases where I wrote down detailed notes or entered them into Anki, I find that I probably recorded a lot more than I should have. So how do you figure out what is worth (most efficient) entering into cards in that case?