Launch Trajectory help

[MDBenson]

Hi,

I have been tooling with KSP for about a week and have already (largely thanks to MechJeb 2.0) got to building stuff in orbit and all sorts of other cool things in LEO. Not gone beyond so far, I want to build orbital outposts at every place in turn then use them for staging for landings etc. It's a bit of a baby steps way of doing it but it's my way

So, on to my quandary. I am using MechJeb 2.0 to autopilot my orbital maneuvers, because I am too cack-handed to do it by hand basically. I am a bit baffled by the differences in orbital launch profile. Now, I'm aware that it may well be rocket dependant and that there's a lot of complex maths behind it. I am a self-confessed match dullard, I cannot wrap my head around it. Are there any 'rules of thumb' I can apply to get a roughly suitable profile or resolve issues with profiles for each rocket by following a diagnostic routine or something? Failing that can anyone explain it in layman's terms (i.e. not descend into Einsteinian maths equations and stuff)?

Thanks.