Catnip (not catmint, though) is an extremely effective insect repellent. Nepetalactone is an insect irritant more effective than DEET.

Serracinia pitcher plants. They are native to N America and they are very hardy. They'll eat the bugs. All you have to do is keep them wet and sitting in distilled or rain water, and plenty of sun. They like the cold in the winter and need it for their winter dormancy period, so you can leave them outside in the PNW (since you mentioned). The plants are gluttons and will eat as much as will fall in their mouths (jst like me, fr fr).

They are such easy plants to grow outside, as long as you keep them wet and use distilled or rain water. They will die with tap water because of minerals in the water.

Keeping carniverous plants is so rewarding, at least for me, especially when I hear insects in the traps, feeding my babies

Marigolds do something, forget what tho

Neem oil mixed with water and spritzed on any plant that can handle it will help deter flies. You could even get a fake plant and occasionally spray the leaves to leave a light residue on it. Some people don't like the smell but I use it on house plants and got used to it. Citronella oil spray would probably have a similar effect.

Sundew is natures flypaper. There are variants native to Northern Europe, California and Australia, so you should be able to find one that works for you

Lemongrass that is used in a lot of Thai recipes is supposed to be bad for insects (most familiar with the effect on mosquitos and fleas). Maybe that would work if you can grow it.

I live in the "pacific north west" basically on the border between canada and the us on the west coast for reference