I tend to hide in the shade at an autox, so i can usually get away with one coating of whatever SPF above 45 i happen to be carrying.
I wear a goofy hat to help with the sun as well:

I have been blessed that I don't burn. I get a nice reddish tan color on my face and arms and then stay that way until winter.
I have had two (2) 'real' redhead girlfriends. Both of them had the temper to match.
Obviously they didn't stick around very long. 