One of the best places to start is by finding out what each aspect of the synth does. Once you know that, you can do things much more predictably rather than having to throw a stone into the dark all the time.
There will always be experimenting points, as this is the nature of programming, u don't know exactly what you are going to come up with until it is there. But by knowing what everything does, it can help you go off in more specific directions.
knowing more about different types of synthesis can help too, also getting info on common sounds made by merging waveforms can help too.
Scott