Door stand - feather splitter????
I presume you mean chopping out hinge recesses, lock mortises, etc before swinging the doors. I've made-up softwood door stands from 4 x 2in CLS for years. Used to make them with a wedge cut from the side, but more recently started to do them with a fairly tight slot and the thinnest of connecting pieces between the two ends so that popping a wedge beneath one of the feet causes the jaws to nip in and hold the door. One door stand is normally enough unless I'm working on huge doors (e.g. old bank doors, etc). I do have a couple of pairs of those Magic Grippers (a present) and they are pretty nifty, but it's yet another piece of kit to carry in the van so I find myself using them rarely: I have to say, though, that on all the new build/extension stuff I've done for a few years the doors come pre-hung - it's only on the refurbs/listeds that I actually get involved in properly fitting doors these days
As LostInTheLight says those Winbags (and the Chinese knock-offs) can be good for getting a perfect fit in the opening (gapping), too, when used in conjunction with graduated horseshoe packers