(1) Sunscreen/sunblock on your face and neck every day, whatever the weather, will go a long way to help prevent some of the aging process. I have done this since I was about 30. I am now 61 and, while I do have wrinkles, I have never had an age spot on my face. (I do have them on my hands and arms, as I have always spent a lot of time outdoors and have not always protected my skin from the neck down.)
(2) Use a Clarisonic, and always cleanse your face/neck before you go to bed--no exceptions. The Clarisonic is a bit pricey, but it does a great job of removing impurities and cleaning out your pores, and it will allow whatever products you use to work better.
(3) Check out the post on this forum about green drinks/juicing. Your skin really does reflect your health, and green drinks will make a difference. If you cut out processed foods, sugar, and alcohol, and increase your intake of veggies and fruits, you will see the difference in your skin in a relatively short time. (And it's less expensive to try than most cosmetics.)
As far as cosmetics go, obviously what works wonders for some individuals does nothing for others because we all have different issues. I have spent/wasted so much money over the years on cosmetics and don't even want to think about all the partially used bottles, tubes, tubs of expensive stuff I have thrown out or given away. That's sort of how I justified the cost of the Clarisonic. More recently I have been using some SkinMedica products that are suitable for my age and my skin issues and they seem to be working very well. But honestly, I think prevention and nutrition--via, sunscreen, diet and proper cleansing--go a long way.
MacBeanur: You mentioned you couldn't find a sunscreen that worked for you. I have complained for years about the same thing (even though I used it anyway) and have tried many different kinds. Recently I came across a SkinCeuticals product called Physical Fusion SPF 50. It is the best stuff I have ever used. It is thin, it absorbs immediately and leaves no greasy/chalky residue on your skin. It is also slightly tinted. I actually use the stuff instead of foundation.