Its very hard for us to just give you a list of tips, typing out a big reply for everyone who asks. You know the name of the two main techniques, thats a good start, hit google with those keywords and you will find mountains of very good detailed tutorials.
If you have more specific questions, I and others will be more than happy to help, and the best way to get some useful tips is to paint up a model and post some pictures, then we can give specific advice on how to improve. If I were to give you one piece of advice though, it would be water down your paints. Multiple thin layers ALWAYS looks better than one thick layer, but it takes longer so a lot of beginners do not do it.