I usually start bracing the back as it's more straightforward than the top. We want the back of the guitar to be pretty rigid and to not absorb the sound of the guitar. On the other hand, we don't want to make it too heavy.
My bracing pattern is a simple ladder brace with a center reinforcement strip. The braces are made from carefully selected quarter sawn sitka. This means that the grain runs along the braces and the cross sectionally the grain is vertical. Grain orientation is a subtle consideration, but in creating a great guitar, it's the sum total of little things that makes the difference.