Overwriting bores the reader, so don’t do it.
Adjectives: avoid them
Adjectives are best avoided: add nuance with a better choice of noun or phrase.
Adverbs: avoid them
Judicious use of adverbs is much more effective than scattering them liberally.
Filter words: how to remove the reader from the character’s head
Filter words remove the reader from the narrative, bringing them out of the world you’ve invented and back to the fact that they’re reading a book. Find out what these words are and how to remove them.
Stage directions: who’s doing what?
Characters do stuff and move about. If we don’t convey this to the reader, our characters might as well be statues. However, too much stage direction risks tedium. We need to get the balance right.