@Shon3i
Denoising should be avoided when you have problems with blocking, because it will only make things worse. I'm assuming you are having problems with blocks on gradients and flat areas as that is the most common problem. A setting of 2:-2 should get rid of most of the blocking without influencing detail to much. If your willing to use a cqm
try this one It should reduce your blocking without introducing any other problems, If you want a sharper picture you could try -2:-2 with the cqm.
@Sirber
I don't encode anime much, but I've got some general ideas that might work for you, of coarse deblocking is quite subjective...
Low- 0:3
Medium- 1:-1
High- 0:-3