I've tried tying my Fissidens on stainless steel mesh, slate and wood. They are all great methods. If you choose slate or wood you can try a dry start method or use super glue. George used a DSM which involved the use of yogurt and blending it with moss and applying it on driftwood. He kept in enclosed in his tank keep the area humid and moist, letting the moss establish itself on the driftwood then filled the tank. You can do this in a container big enough to fit a slate or driftwood that you would like the moss to attach to.
The super glue method I heard from Nathaniel works nicely also. You want to use Cyanoacrylate super glue, the gel form works very well as it allows more time for you to work with the glue and the glue won't run everywhere. Just apply a dot of glue and get a few pieces or a single strand of moss and place it on top of the glue applying a little bit of pressure. The only downside of using super glue is that it will leave a white residue on the surface of the object you attach the moss on but eventually the moss will cover the spot and it won't be noticed. When you have finished you can leave it to try while misting it to keep the moss wet or just put it in the aquarium, the water will quickly harden the glue, and I mean quickly. Its shrimp safe and fish safe too!
You can use the mesh method and tie the moss with string/fishing line, the latter is preferred as it won't degrade at least not as fast as thread/string. The moss itself won't attach to the mesh unless the surface is not smooth. Like the mesh you can also use thread/fishing line to attach the moss to wood and stones and the moss will eventually take hold. But in some cases due to the shape/size of the object, tying the moss maybe prove to be difficult, this is where the dry start method and glue comes into play.
All our moss has detached itself from the wood and we're talking a lot of moss. Had to re staple it today and ended up throwing Out most of it, I think increasing the flow rate is what did it to mine. What Nathaniel did was brilliant very patient too can't see me sitting doing that I have noticed that some mosses attach there selves over time and some like to be free
I got my mesh from Homebase. I used some nylon butterfly netting over the top to hold the moss down and sewed around the edges. Very quick, very easy It took about two weeks for the moss to grow enough to start hiding the netting.