Shooting in RAW is a good idea, as it gives you plenty of opportunity to boost colour later on. However, the first two things to look at are done in-camera.
- Proper exposure. If your over- or under-expose, your colours will not be as full and saturated as with a spot-on exposure.
- Proper white-balance. Your camera's auto white-balance (AWB) has a tendency to neutralize colours. Pick a white-balance setting that is suitable to the occasion - play with it and see what you like!
You can use all kinds of post-processing tricks, but a photographer of course should do as much as possible right in-camera.
If you post one or two photos (including EXIF information) we might give more detailed help.