I try to spend some time in the sun in warm weather, but not to overdo it. It is my understanding that it can be bad to get too little sun, just as it can be bad to get too much.
Sometimes I enhance the skin color somewhat by using a sunless tanning product.
My favorite brand is Bain de Soleil.
I have not tried the following brand, but it looks interesting.
Produces A Golden/Brown Tan Without Tanning Beds Or The Sun!