Posts:
I upvote any post I like enough to want to see again. I downvote any post I dislike enough to not want to see again.

With this system, upvotes are favourites (search votedup:* instead of favoritedby:*) and downvotes are blacklisted (search -voteddown:* instead of flooding my blacklist with post IDs). My favourited post list is private and my blacklisted post list is potentially endless. It also leaves the actual favourites function open for other uses.

Comments:
If it's funny, witty, intelligent or agreeable, I'll upvote it. If it's cringy, RP, hateful, illegible or gibberish, I'll downvote it. If it's too obvious, boring or "I (dis)like this.", I'll ignore it. My standards on each of those may be different from those of others.