For Genre Easy modes you can use pre-watched shows, so just filter your list to completed + by genre and try and fill out the "harder" ones with specific reqs first
then you can do the "easier" ones like different studios and airdate ones for the normal and hard modes.
also sign up for them as early as you can to count later shows as you watch.
the "collection" challenges have specific shows to watch that you could count for both.
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back before I completed most of the genre ones, I tried hard to micro-manage and fit as much as possible by double/triple/quadruple-dipping between other genre/collection/puzzle etc. challenges but it's a very quick way to burn yourself out by making watching like a chore rather than earning points as a fun bonus.
and it's very important to not spend too much time planning ahead as listed genres or tags can change.<hr>AWC has a website with a code generator tool to make planning easier and to make sure the formatting is correct, but it doesn't error check for you.
https://anilist.co/forum/thread/49297 https://awc.moe/challenges/editor