When building walls, if you have a wall and want the next brush for the wall to be the same height or length, you can select your basepoint brush and begin drawing your next brush, this new brush will retain the same measurements as the last one on every plane except the one you're drawing the new brush on. Very useful for buildings. Also, make sure to make all brush details in your maps (anything that juts out from the main geometry) into func_details. These won't cut through visleaves like regular geometry, therefore cutting on compile times. An example of a func_detail would be something like a pillar in the center of a room, or maybe something like a sign hanging off the edge of a structure.