this is a link discussing the options I was asking about, interested what peoples preferences are and why
Tying Off For SRT
Limb cinch with throwline pull-down
Either of the previous two tie-offs will be more effective if pull-down capability is added to the system before climbing. This will eliminate the mandatory necessity of climbing all the way to the top in order to be able to retrieve the rope from the setting, and will facilitate recovery of the rope at climb's end.
Simply tie a length of strong line (or even another rope) to the loop in the running bowline, or to the delta, before hauling the cinch all the way to the top of the tree. This way, in case the climber should so wish, the cinch, and the rope, can be retrieved by simply pulling down on the line and bringing the cinch back to the ground.
The upside to this is obvious. The climber can now retrieve a rope without necessarily having to ascend to the anchoring limb to do so.
The downside is that there are now things that can go wrong. If the string/line being used for the pull-down is not strong enough, it might break before bringing the cinch to the ground. There is a further issue with the potential to get tangled in the pull-down line while climbing. Serious line management is necessary here!
Mid-line limb cinch with rope pull down
If your rope is long enough, a mid-line cinch can be created. For this one, a delta (or similar item) becomes a serious necessity. Do everything as before up until the point when the rope passes over the anchor limb. Then tie a F8OAB (or anchor hitch, or any other nice mid-line knot) in the rope at your side. Insert delta into the loop created, insert rope into delta, and continue hauling until the limb is cinched. If there was enough rope the climber should now have a cinch in place in the tree and both ends of the rope on the ground. The rope itself will function as the pull-down.
The upside is that the rope itself functions as the pull-down and no extra string or line is necessary.
The downside is that you need a rope that is twice the length of the height of the setting in order to have both ends on the ground.
Limb cinch on continuous loop
First, pull your rope up, over the limb, and back to the ground. You will need a rope twice the length of the height to your setting. Once you have both ends on the ground, tie the two ends together to create an endless loop (I usually use a figure eight follow through, or re-threaded figure eight, whichever you choose to call it). Then a F8OAB in the rope on either side of the knot at least a couple of feet away from the connection knot. Insert delta in the loop of the F8OAB, insert rope from the other side of the setting and haul the cinch right on up to the limb.
This is my favorite way to do a limb cinch when I have enough rope, because now both ends of my rope are at the top and I don't have to haul an end up with me to advance the climb. Once I have climbed up to the cinch I simply separate the two ends of the rope and use the end not involved in the cinch to create a new DRT setting for advancing the climb. Once the new setting has been created and I have transferred my weight to it, I can de-rig the cinch, pull the rope off the limb and continue the climb, using both ends of the rope. If I don't ever reach the top of my entry pitch, for whatever reason, there's no problem because I have a convenient pull-down ready to go.
The only downside is that it takes more rope than a simple cinch with delta or bowline. Take care always to make sure that you are climbing on the side that has been cinched, rather than on the pull-down side!