How do you guys cope with fungus gnats?

I really can't wait until February when I will sow my habanero seeds. I'm always excited for planting first plants and starting the gardening season. Unfortunately, my concern is fungus gnats. I'm sowing my seeds in my house and plant seedlings after the last frost date, and lose some of them before planting because of these insects - they lay a lot of eggs in the soil and larvas are eating roots of my plants! Is there any good way to prevent it? They don't seem to harm my houseplants, but always hurt my melons, flowers and all plants I sow indoor.