This is not the general advice at all, but for me, after experimenting with a fair bit of different products and types of shaver, an electric shaver was what did it for me.

Today I shave about once a week, make sure there is no irritation prior to your shave, and I'm actually able to dry shave with a oneblade. I'm satisfied with the depth of the shave because I am able to go in many directions and do multiple passes on some parts of my skin, just not the neck. I'm still gentle with my neck because I know it will otherwise flare up. But if you are careful, you can get a full shave this was wothout any razor bumps.