What works for you can only be determined from practice and trial and error, unfortunately. There's no one good way to start, or which direction to go when building.
But a few very very very important thing to keep in mind is to keep it clean:
-Cut as cleanly as possible
-Be sure all of the numbers line up with their corresponding piece, If you are a off on one spot, it will have a ripple effect and throw off a later piece even worse.
-Sharply fold all fold lines and tabs, it's important for keeping the piece accurate, clean, and strong
Take your time, be meticulous but don't wear yourself out. If you're using hot glue, remember that you can always undo errors! If you're using PVA glue... be very very VERY careful!