I figured since I was doing it I might as well take some pics and maybe help out someone that has never done it before or to spark the interest in someone that has never tried it and might want to now.
Anyways, here are the supplies you'll need:
Scissors, spray/misting bottle with water, sewing thread (you can use fishing line as well but it doesn't dissolve over time like cotton thread does), a piece of driftwood or a rock will work as well, and of course some moss (for this one I used Christmas moss).
Optional: Super glue (you can actually skip this completely and just use super glue but it leaves a white residue if it gets wet before completely curing or to instantly cure it if you don't care about the white spray some water on it and it will cure instantly).
How I attach the thread to the driftwood, tie a loop in the end of the thread and pull the tag end of the thread through the loop.
Then you wrap the loop around the driftwood and cinch is down and keep pressure until you wrap it a few times to lock it on the piece.
I like to chop up the moss a bit to make it easier to work with and I feel it helps to stimulate new growth.
This after a bit of wrapping the moss at the starting area of the driftwood
Don't be afraid to go crazy with the angles of thread aka go every direction you can to secure the moss so it doesn't float off when you place it in the water.
I like to start at the end point and work down to the base for two reasons. One it gives some more "bite" having the thread wrapped around wood to break up the smooth surface and two I can anchor the thread better at the base and bring it to the next section. One other thing I learned tonight is when I get to the end of the branch to wrap it a few times and hit the thread and end of the branch with some super glue to secure the thread from slipping off the end of the branch! Let it dry or hit it with some water to cure then place the moss over the white ugliness lol.
This is how I set the moss on the wood before wrapping it, note that for the best results with moss, try to get it on the object you're tying it to in a single layer. The reason for the single layer is moss tends to brown and look bad on the lower layers if you layer it, so take your time and place your moss as carefully as you can to avoid this.
Then wrap it and secure it down.
When you start to see this you should mist the piece to make sure the moss doesn't dry out completely while you're working on it.
Make sure you tie off the thread well with a good tension to keeps things nice and tight, then mist it again, and sit back and admire your work! Finished product (was running low on moss or there wouldn't be as many bare spots on this but I am happy with the results, it'll fill in in a month or less). One note is don't bother covering the bottom of the wood if its not going to be facing the light don't waste the time and effort covering it as it will slowly die back in my experience.
I hope this helps someone or at least encourages someone to give it a try!