To boost sunblock protection, find a Vitamin C serum that one's skin likes. It also helps brighten the skin over time. Timeless Skincare makes a couple - one being their Hyularonic Serum with 5% Vitamin C(I started with that and it's great), and their C + E and Ferulic Acid one(20% Vitamin C) and Vitacost has their house brand, CSI Youth Serum(12% Vitamin C) Right now I'm working in the CSI one while finishing the Timeless milder one, before advancing to Timeless full-strength(20% C)that gets great reviews even by people who have finicky skin. Anyhow, using a C serum during the day under moisturizer and sunblock really does help with boosting the sun protection as well as the other benefits it has.
@Swest - I'm with you on the not being super-white(I'm light-medium that used to tan at the drop of a hat what with my yellow undertones)and also not wanting a single new sun spot or freckles. As we get older, if we tan, we tend to get blotches and spots rather than that nice even tan. Getting too tan as we get older makes us look older in addition to the skin damage it's creating. I don't use sunless tanner - they smell really bad on me such that I couldn't stand it whatsoever. Also, if one has ANY spots or freckles, self-tanner doesn't blend them in, it makes them darker. Not the look one is going for!:(