I hope you are talking about doing 3D surfaces.
Are you using EnRoute Pro? If so, you have plenty of 3D tools. Play around with them to design your part. You can even import them from something like AutoCad and create a surface from a mesh.
Once you have your shape created, continue doing your step rough, then use a ballnose bit and try an island fill. For good work, make sure you do a fine overlap on your final pass - say 90% - 92% overlap.
There are a lot more tricks to it, but if you saw someone do it once, you'd have a lot better understanding.