Hi I get a pretty bad rash on my neck when I shave it. I use an electric shaver for my face which is fine but if I use it on my neck it will tear it up and make it sore. I have tried just doing a dry shave with a normal bic two bladed razer and also a wet shave but no luck. I recently have been using nivia for me shaving foam just for my neck when I shave it and also nivia for me after shave on my neck but no look. I even just try and do an half assed job of shaving my neck to prevent worser rashes as the longer I seem to spend getting all the hair off the worse of a rash I get.
That used to happen to me as well, my body just built up a resistance against it and now it's ok. If you are using a regular bladed shaver then I suggest the following. Run warm-hot water on your face to open the pores so the hair will cut easier, lather on the shaving creme well, move the blade slowly as you shave, and make sure to put on aftershave afterwards.
Also I've found that shavers with more blades cause less irritation.
I shave when I get straight out of a hot shower. The razor (I use Wilkinson Sword Quattro) just glides off the neck and never cuts. The key to a clean shave is preparing the skin and making sure you have a decent razor. Two-blade disposables are terrible.