I'm not as experienced at this as others here, but I've been really impressed with the results I get with a simple 3-step process. I use Pedro's Green Fizz bike wash first, but I think warm water and dish soap would work as well. I use a dish scouring pad and give the bike a good wash to remove any oils. I'm not very aggressive here and avoid the decals. I then wipe it down with a towel. The finish usually looks pretty dull at this point. I then wipe it down with Pedro's Bike Lust Silicone Polish. This really works for me to start and see some color start popping back. I'll finish it off with a good auto wax lightly applied, dried, & wiped off with a fine towel. This method has brought some pretty crappy looking bikes back to a very attractive gloss.