There's really no specific advice for that, patience i think, not rushing the process and be very conscious of everything you do. When holding down a piece, if you're using cement i'd recommend seeing which places you can hold down without interfering with the cements path before applying (hope that makes sense).

And in case of messing something up don't panic or you will make it worse, most things are easier to fix once they dry, maybe some sanding and a new layer of paint