make sure your building surface is flat, or even.lol
get weights
use sanding blocks ,bars..ect.
wood grain going in the proper direction.
get a triangle and cut the 90 deg coner off...for verticle stab alingment.
measure twice...cut onces.lol

have extra balsa or tristocks ..incase you deem certain
area needs re-enforcement... or you goof.

do inventory first before building.
mark parts and sort to building sections or sequent.
this will help alot .