1. If you can't or don't want to get the area waxed, make sure you have plenty of light so you can see what you're doing.
2. Use good, new razor but but be careful not to get shave cream on the "sensitive" parts (not sure if i can say exactly what parts I mean) or if you do rinse it soon as you can or it may cause irritation.
3. Only get the parts you are physically able to see, you don't want to cut yourself by accident. You can maybe get someone you trust to help with the places you can't see.
Edit: I just realized the OP said this is something requested by the boyfriend. Thats great and all, I have heard that doing that together can be kind of sensual, as long as both agree to it. If the OP is okay with him wanting that, its all good. It is after all her body and her decision. Hope this helps, good luck.
waxing is proabably safer, shaving might leave you with irritation and spots if not done correctly