Score 4: Cliche, annoying, and meh. Usually this deserves for your random 12 episodes anime which only contains ecchi stuffs, sex jokes, boring school life, NTR, or moeshits. Also shallow characters.
Score 5: Same contents like what I give for score 4. Only I kinda enjoy its humor and not very annoying like score 4 ones.
Score 6: Usually I give this for any anime which was promising but lacks a lot of things like shallow characters, generic story, too MC-centric (MC-centric means only MC can solve all and things focused very much on the MC). Also sometimes contains a big number of annoying plotholes.
Score 7: Decent. Nice pacing, but usually lacks on characterizations, and also usually generic story with some annoying plotholes. Sometimes promising but eventually become a bit disappointing. Still enjoyable, though.
Score 8: Good anime. Nice pacing, good characterizations, good story. Not too fast and not too slow. But sometimes lacks with the poor villains' motivation, or plotholes.
Score 9: Wonderful anime. Perfect pacing, great story depth, great characterizations, almost no one being dumped. Sometimes contains plotholes, but they aren't annoying at all. Almost perfect.
Score 10: Honestly there are no score 10 for me. Because an anime, whatever the number of episodes, less or much, can't be very perfect. There will be always a flaw, even though only a little bit.
For scoring: Sometimes I give scores to some anime with 8. But that doesn't mean I give a pure 8 score to those anime equally. Score 8 can be 7.7, 7.8, 7.9, 8.1, 8.2, or 8.3.