Any "bad bug" solutions that don't deter good bugs? [View all]

I just potted a bunch of plants (going with container gardening since I'll have to shift their location due to diminishing sunlight in the backyard) and already see the pesky flies (I guess they're also called gnats but they sure look like little flies to me) on nearly everything, which makes me think it was the super rich soil I used. I did create a mixture for the container soil but oh well...

Anyway, I'm wondering if doing things like rubbing essential oils like rosemary and peppermint on the rims of the containers would suffice in deterring the bad bugs but I don't want to repel good ones. Googling isn't being helpful in this regard so far.

I did spray an organic garden pest solution on the soil itself, and I will get marigolds to place in the various container areas. Still, I'm really curious about using essential oils as a deterrent so long as ladybugs and others aren't deterred as well.

Any experiences in this regard? Thanks!