Avoid the ecstatic adjectives that occupy such disproportionate space in every critic's quiver - words like "enthralling" and "luminous."
Not every oak has to be gnarled, every detective hard-bitten. The adjective that exists solely as a decoration is a self-indulgence for the writer and an obstacle for the reader.
Most writers sow adjectives almost unconsciously into the soil of their prose to make it more lush and pretty. The sentences become longer and longer as they fill up with stately elms and graceful boughs and frisky kittens and sleepy lagoons.