let's say I want to unwrap the grips, and I need to unwrap it into a different island instead of 1 big island right? How do I choose which part to become an island?
Good question, and this is really important! Where you place your seams has a big impact on your texturing and especially normal bake. This course goes into that in-depth: https://cgcookie.com/course/intro-to-normal-map-modeling-for-games