I have found my greatest success fighting Yellow Jackets is with early trapping in the spring. I purchased numerous traps and set them out in various places around my property and bait them with attractant and sugar/soap solution, I have heard raw meat works well too but never tried it. We suspend a cottonball soaked with the attractant and hang it inside the trap allowing the lure to be more effective.
In the spring the Queens are the first Yellow Jackets you see, they are looking for food and a place to make a nest. Eliminate the queen and you just eliminated 1000's of pesky workers. The queens are larger and easily identifiable once in the trap.
We set our traps along the wood line of the property. There is nothing behind us for a mile but a creek, woods and a 100 ac. soy field. The first years we started setting the traps we set them out in late Feb. because for us the temps can start to rise into the 70's during the daytime. It is amazing how many queens we trap. By May we stop seeing many trapped queens and the actions dwindles and then workers are showing up, but not many. We keep the traps up through the summer to hopefully trap any remaining workers.
The best part is how much of a reduction in the yellow jacket population the trapping of the queens makes. It used to be a constant reminder about how heavy of an infestation of yellow jackets we had. Then it was not even a thought. We rarely saw any and forgot of the past issues we had. I have to be vigilant about removing the traps in the winter and rebaiting in the spring because we simply do not have the reminders, aka stings, buzzing, robbing hummingbird feeders, ect. If you have issues, then try the traps they really work.