I agree. One challenge that can throw people at first is that you really do have to forward think how you're approaching the work (ok, you have to do that with any design) *but* the beauty is that it's always real easy to go back and change things with the parametric approach.... *IF* you haven't overly-constrained your design. So my advice would be to really keep the constraints down; don't over-spec the drawings beyond what you need. Trust the software to work it out; define things like centre-lines on your face early on and then work from that, for example, as the driving dimension.

kingcreaky, if you want a demo/lesson in Onshape I can at least help you with that - maybe it will lend across to F360 easily too.... ;)