Comp tool and multi-track drums

So I have an upcoming session in which I will be adding drums to an existing session of Keyboards and Vocals. Not recorded to a click. I am anticipating the possibility of more than one take, or punch in's.
 
I am about to embark on reading and seeking various tutorials so not really asking the basics. I'm more interested in any solutions to unforseen gotcha's and or tips or tricks to smooth the process of learning etc.
 
Thank you.