As promised hackwire, here is how I anchor to the door..

This is the knot on the anchor straps. A simple knot, nothing special.. its purpose is to make the end bigger than the space between the door and the door frame so the anchor does not slip through.
Here is how to put it on.

I'll be pulling the the straps from the side where the door close, thus all the force from the pulling is spread onto the side frame instead of just on the door latch/knob if I were to pull from the other side.
Once you put the anchor on top, pull the door to close. Then pull the anchor tight until you feel the knot is stuck on the other side.
Here is a picture of how the knot on the anchor get stuck and stop the anchor from slipping through.

Well that's about it. By the way, using separate anchor for each suspension straps and setting them up at about shoulder width apart allow the row/pull up exercise to mimick real pull up better as when you lean back, the hand is straighten at shoulder width apart. If using one anchor only, the hands will be close together as the handles are pulled until it is side by side.. Thus pull up becomes more like rowing.
On another note, here is a picture of my Bulgarian bag.