what jona said sorta made no sense to me but you just gotta start out on any old flat box for front feebles and the angle iron or coping should be jammed into the space in between your drop out and back wheel, I like to keep my weight back a little like I'm pushing off the box because it will prevent slipping out, which, if your drop out is not completely on, will likely happen.
For backlips about 90% is just hucking it, you just have to throw it and try to find your balancing point, it's much easier if you can front board well.
Hope this helped!