I usually just do the pull downs with my back on the board, alternating side to front pull down. I don't really pay attention to how many reps I do, just to the point when I feel nicely stretched and loose. Then I'll switch to the row position with my butt towards the lower end of the board and do a full motioned row where I'm getting a nice stretch, pulling forward toward my chest as a bicep curl motion then to the side elbows pointing outward with my back straight then back down to a full back stretch. I'll do this for 10~15 minutes.
I've also thought about adding a weighted helmet or hat of some sort to stretch the neck. What I do now when I hang is I'll rotate my spine side to side slowly making sure I'm stretching as many back muscles as possible. Usually I'll hear a snap crackle and pop doing this. It kinda feels good. :D