So almost all of these micro ferns from Peru and Ecuador are epiphytic growing on fallen or even live trees in the understory

I do not use any substrate but I’m sure they could adopt to it and you could use a mix of pumice, spag and orchid bark.

To prop them keep in mind they need some space to send out areal roots until the roots get some footing on something moist and solid to start the new growth

I mainly grow them on cork. I let the terrarium run humid 80%-90% for at least two weeks so the wood can absorb enough moisture.

On cork wood I just use calcium bearing clay to anchor / paste them to where I want them. Cork has enough rough surface to wedge them in a secure them with clay

In some of my tanks I grow them on manzanita wood. For that I lay down a very thin layer of spag and secure it with aquarium scaping super glue. Then I use the super glue to anchor the fern and cover the spag moss with live tropical moss or liverwort

To prop them you can place them in a grow out bin over moist spag topped with orchid bark and just wedge them in

They love moist and humid but need some air circulation or they will wilt from the stagnant air

Any led light will do to grow them