if your new to shaving, u want to shave with the grain, therefore your head will get use to feeling a razor. i used to use the Mach 3, Profusion Glide, bascially i used to use Gillette products. thing was, it was a close shave, but it way TOO close, meaning i would break out extremely bad. look liked ants had a camp all over my head.
nowadays i used Shick Hydro 5. in my opinion, the best razor i've ever used. Plus i can shave against the grain without worrying about cutting too close because they have skin guards, which i'm assumin it reduces the irritation on your skin.
best advice i can give is, let your head heal up for about a week or so. then give it a shot. go ahead and shave against the grain.
after you shave, apply cold water. gently dry your head, and then apply sunscreen & aloe vera. this seems to do the trick for me.
