We've had wasp problems around my house for several years. They like the eaves of the house, the utility trailer I rarely move, and any other spot they can find out of the rain. I have found that diligent killing in the early spring significantly reduces the number of nests for the rest of the year. If you can catch the nest when it starts and there's only one or two wasps it's like you kill the queen and there aren't many new nests after that. I killed 5 or six nests about 6 weeks ago and haven't seen a new one since.
I tried the big fake nests a couple years ago but it didn't help. I just buy stock in spray cans now.