Avoid “slow motion”
If you detail every space, every corner, every gesture; then the important events will become less meaningful in the novel, even getting lost in between pages and pages of irrelevance. We have to choose carefully what is going to get carefully described, that is which is important in the story.
Don’t describe things ‘going around’ the characters and events. Remember to involve the actor and the action in the description. The reader doesn’t want to know what’s in the background, he wants to know everything at the same time: Who does what, where and why… and if he can guess what the consequences are.
Keep in mind what you wrote before and why. Know the scenario well before communicating it to the readers. Remember they’ll discover immediately the slightest inconsistency and that destroys the rest of the story’s credibility.
Avoid the boring bits
A description must be necessary because the moment your readers find paragraphs where the story doesn’t seem to change they will jump ahead. If it is unnecessary for the complete understanding of the character, avoid stopping to describe:
Drinking coffee, making coffee, any inner-monologue about coffee and its derivatives from the Starbucks’ menu. I love coffee, but this is already way too overused.
It seems ordinary for your character to eat out if he’s between the ages of 21 and 35. Always. Every day. I’m guessing it has something to do with American sitcoms like Friends and Sex and the City. Don’t go that way. Your characters can become regulars of other places like parks, museums, vegetarian shops… even camping, outdoor cinemas or even the moon, if you’d like. There are no restrictions; you can pick any place you want as long as it’s interesting.
It has become a classic to stop specifically to describe the prep the character makes in order to go to work or go out, how he grooms, how he dresses. It tends to become boring if it’s not indispensable.
Travel in general
If the character’s movement doesn’t involve some sort of relevant conflict, delete if from the story.
To sum up
Be specific, original, concrete, as short as possible and consistent. If you can also amaze with an imaginative prose and express the correct emotions, you have an unsurpassable description in your hands.