I always use thicker paper (200 gsm, or grams per square meter). That's about 2.5 times as thick as regular printer paper (usually about75-80gsm).
Thicker paper makes the final model stronger and it holds its shape easier. Another very easy tip but one that makes a big difference, is to take the time to colour the edges of the paper with a pencil or marker in the colour of the part. That way, you won't have "white lines" on the final model: www.youtube.com/watch?v=hhBuuEVSUcw
This build is GORGEOUS! I finally ended the building, it looks really awesome on my desk Furthermore, your instructions were great too and easy to follow for a beginner, but damn, the hair is soooo hard!