How do you get rid of fruit flies indoors?

use a net and sticky traps.

There are many ways and things you can try To get rid of fruit flies. I personally recommend that you use a vinegar trap. It is efficient and not hazard's. All you need to do is to pour some vinegar into a source. Then make a cone out of paper with the one end small enough for a fruit fly to go into. The cone must not touch the vinegar. The fruit flies will go in because they love the smell but they won't know how to get out.

For more information try: http://www.thebugsquad.com/fruit-flies/getting-rid-of-fruit-flies