Moss projects are
really easy. All one needs is a the dedication to keep them moist, but even then, when a planting does dry out (ala a vacation) it's not much of a set back because all that's needed to revive moss is a rededication to keeping it moist. As a bonsai practitioner with a couple of hundred plants, I'm doing the watering rounds daily anyway, so it's not much of a chore to see to a planting's moisture needs.
This (below) is part of a stump from a pear tree. After I cut the tree down, I piled brush on the stump and burned it before I dug it out. I put it in a plastic tray with some gritty mix in the bottom, and started to water it. Mother nature did all the rest, except for the 2 live plants you can see in the images, which were cuttings I had for no reason in particular. Below you'll see it in Aug of the first summer. There are a couple of featherstones in the mix too, but they are already covered by moss. The small plant with the Osmocote prills above it is a Ficus pumila. Not sure why I used it as I knew it wouldn't tolerate the winter. I guess just because it was handy.
Here, you see the featherstones before I added the stump:
Below is the back side of the first image. The other plant matter is liverwort, which rode in on the wind (I didn't plant it).
This is the same planting, a summer later, with the Ficus gone under and a bittersweet vine in it's place. The moss is making good progress insofar as covering the stump. I left the planting outdoors in a Michigan winter and the plant died from getting too dry (not the cold). Currently, the moss is a thick matt covering everything. Nuthatches love to hide sunflower seeds in the moss (which germinate and get pulled out with tweezers), and birds love stealing it for their nests, especially chickadees.
This and the next 2 images below are front/back of a little project consisting of about a 3x5x3" mini-loaf pan (dollar store) I drilled a bottom hole in, a branch elbow from a cedar tree on top of gritty mix, and a Ficus pumila cutting. The image was taken last year in Oct when I brought the planting in to grow under lights and controlled humidity.
This is the front view of the dish planting a little later in the winter, after the cutting was fully rooted and had grown a bit.
I keep them in the shade outdoors, and under 6000K LEDs indoors. All I do is spritz them with tapwater with a hose or hand spritzer twice per day unless it rains. I add a few drops of Foliage-Pro 9-3-6 from time to time, and that's about it.
You can make miniature moss gardens in large bottle caps or small food containers. I like to make a hole in the bottom, half-fill with a little potting mix, and nestle a pine cone, interesting piece of a branch or wood, or something else that supports moss growth, and wait until they look good and give them to all sorts of people I come across during my travels.
Sorry it looks drab. I just ran out to snap a picture. It's been out in our winter w/o water and I didn't clean up the lid from a container of DWs skin moisturizer (about 3" wide), but I hope you get the idea.
Al