I have. Why? What have you got in mind?
It takes a lot of fibre to weave something and that means a lot of preparation & time.
Weaving is basically over and under, over and under..... and then back the way under & over, under & over...... all a loom does is create a structure that lets you lift all the overs and unders apart together to create a *shed*; that is the space that allows you to pass the bundle of weft fibres through, and then allows you to pass all the overs down through the unders to create the *other* shed. Try it with your hands...put both palms together and lift your fingers....one shed, now put your right hand fingers through between your left hand ones....second shed.
If you really want to weave cloth, google for Backstrap loom. Maybe Navajo blanket loom...warp weighted looks simple but it takes an awful lot of setting up. If it's braids and straps then look for South American links, Africans do them too but the S. American ones are simpler in structure if not in weave patterns.
If you want mats from something like rushes then first decide the size you need. Then take a couple of sticks the width you want your mat to be and fasten one to a stable point (tree or stake of some kind) with a loop that will allow you to pull firmly against it but will allow you to work on the ground too. Next you need the warp cords, nettle is very good for this. These cords will need to be as long as your finished mat plus a third and if you can make them double this length even better, lets you fold them over an end stick rather than knotting them on. How many warps is up to you but at least one at each end and one in the middle and better if five or seven. The idea is to *twine* the warps around bundles of rushes or grass or bracken. Basically two cords are wrapped around each bundle but pass over each other too. Imagine untwisting a piece of rope and fitting a bundle of stuff into every twist, but you are creating the rope part as you weave around the bundles. If you do the two end warps first you can then tie these onto the second stick and loop this onto another stake to create a tension. Work the middle warp the same way and then fill in with the others.
If you want a tapestry/ panel piece then four sticks checked together at the ends will create a stable frame that you can wrap with warp threads. You can either just weave in and out of these or use heddles to lift the shed apart.
Weaving can be as simple or as complicated as you choose to make it.
Now then; what are you up to?
Cheers,
Toddy