Yeah, sunscreen has to be reapplied every 2 hours or so, and make sure it has both UVA and UVB protection. Without broad spectrum protection, you're still going to get sun damage. And sun damage basically equals getting tan. Look for Avobenzene (which may also be listed as Parsol 1789 or Butyl methoxydibenzoylmethane), Mexoryl SX, Mexoryl XL, Tinosorb, Zinc oxide, or Titanium dioxide.
Upping the SPF won't really make a big difference, SPF50 should be fine. Don't forget to put on the sunscreen at least 15 minutes before you go outside, 'cause it takes that long for most of the active ingredients in sunscreen to absorb into your skin and start protecting you. Also make sure you're using enough product. Most people don't use enough sunscreen to have it be effective. An example of how much sunscreen is needed is that to properly cover your face, you need to apply about one ketchup packet's worth of product!
Also sunscreen should always be applied last, after all of your other lotions or medicines. Make sure whatever you put on absorbs and dries completely before you put on your sunscreen. (The exception is if your makeup also has the above good ingredients and SPF15+. Then you can apply makeup last.)
A good way to exfoliate effectively and cheaply is with a washcloth + baking soda in the shower.
Where did I get all this info? LOL from
http://www.sunless.com. That website has some amazing people with great advice on how to deal with this kind of thing. I used to be a big sunless tanning fanatic and now I've gone and converted to the "the paler, the better... forget about being tan" club LOL. If you want advice on how to sunless tan your upper arm/shoulder area to match the rest of your arms on your wedding day, check there.
Sorry for such a long post, I'm kinda a sunscreen freak hehe. IMO, sunscreen is THE best "beauty cream" out there. No sun damage = less wrinkles. Less wrinkles = yay! If only I had been smart enough to understand why I shouldn't have gone and fried myself in the sun when I was younger lol.