1. hot on the left, cold on the right
2. sh*t flows downhill
3. don't bite your fingernails
Seriously though, pvc and cpvc are pretty easy to work with. Try pitching your drain at least a 1/4" per foot of run, but if this is just a sink that will see nothing but water/sanitizer solution, you could probably run at 1/8" per foot and still be ok. Also, leave a window a crack while using the glue and primer. If not you might find yourself with an unintentional buzz and SWMBO tends to complain about the smell.