I used Neem from the onset of my most recent grow and it seems to have helped. Before I planted the seeds I diluted pure Neem with water and sprayed the inside of my "nursery" (where I germinate and keep the seedlings for a few weeks). I also sprayed the entire surface of the containers plus the top of the soil around, but not directly on top of, where I planted the seeds. I sprayed again once a week later and once again when I saw a small flying pest.
I have spotted nothing besides the one small flying insect. The plants are now in the big tent and are healthy and happy. I will always use Neem during the "buggy" months!