I have seriously had an extremely difficult time dealing with this until earlier this year.
My friend Caren recommended trying Boudreaux's Butt Paste. It's supposed to be for diaper rash, but as I discovered, it can do amazing things to heal bikini bumps.
It's not the "cure all" that I wish it was, but it is the best thing I've come across on the market.
My other recommendations are to use a brand new razor when shaving, use plenty of shave gel, and take your time. When I get out of the shower, I start by putting some baby powder on the area, then I usually rub on the butt paste.
This stuff can be found in the baby aisle at Target!