Answer:
In addition to other answers to similar questions be sure to get a wasp/yellow jacket trap with an attractant that will entice more than one kind of wasp/yellow jacket to the trap...and prepare the trap with an actual attractant made for the trap instead of sugar water so that honey bees with be less enticed into the trap. Clean out dead insects and replace the attractant regularly.
As mentioned use hummer feeders with protected feeding ports with either ports that have openings too small for wasps/yellow jackets to enter or are positioned above the liquid so they can't reach the sugar water or ports with protected openings such as having flexible valve type openings.
What I did not see mentioned was washing feeders regularly in vinegar diluted in water. I use 1 cup of vinegar in a gallon of water...then rinse well in plain water. This cleans very well, hinders mold growth and seems to prevent wasps/yellow jackets being attracted to the sweet odor of sugar water. IMHO even using a drop of dishwashing liquid and rinsing well still leaves a sweet fragrance that attracts wasps/yellow jackets to feeders.
In between complete cleanings and refilling with fresh sugar water...I wipe the outside of each hummer feeder with a clean paper towel moistened with water diluted vinegar to remove sugar water sprays the hummers themselves splatter on the outside of the feeders from flicking their tongues. Those splatters and dribbles on the outside of the feeder and feeding ports attract wasps/yellow jackets.
I've read that the color yellow attracts wasps/yellow jackets. Many hummer feeders have yellow "flowers"...but as long as I clean my feeders with diluted vinegar in water having yellow on my feeders does not seem to make a difference.
