Don't always use the same words over, and over again.

Use more colorful words.

Example, instead of using 'said' you can use 'reply' or 'answer'

Have variation, don't be repetitive.

Why? Because it's overall more descriptive—it shortens the message you want to get across while painting a more accurate picture of the situation in your readers' pretty little heads.

Example:

Instead of,
She ate the food quickly.

you can have,
She devoured the food.

Devour just holds more impact than "ate." While I'm not condemning these words, using a wider range of vocabulary can help freshen your writing and offer more descriptive scenes and actions. When a reader thinks "ate quickly," then they think of someone... Eating... Quickly (yeah no sh*t, Sherlock).

But devour—that's flavor. That's devour. The readers think, "damn, she must've been real hungry. Probably just swallowed the thing whole."

It's that spice, that is oomf to amp up your descriptions. OF COURSE, you use these sparingly—why?

Using these sparingly make it have more impact. More meaning. The reason why "eat" is so bland is because it's used all the time.

It's all about balance, kids. Find it with a thesaurus and a dictionary.