I didn't find plaster scenery to be a mess at all. The most difficult part is putting the screen in and making sure that it's properly supported. I used aluminum window screen: it cuts easily with scissors, can be shaped somewhat, and will support itself better than fibreglass screening. Watch out for the pointy ends, though. Fibreglass screen will work too, but requires more support. I didn't try it, but I've read that wadded-up balls of newspaper will work well for this task. Simply remove them (or not) after the plaster has set. Steel screen will work, too, but you'll end up looking like you were attacked by a flock of irate chickens (lots of sharp and pointy bits) and the little bits can be attracted to the locomotives' motors.
For plaster, I used a product called Durabond 90, a patching compound the is very strong and hard. While it's made by Canada Gypsum, U.S. Gypsum has a similar product. This stuff has a catalyst in it, and the "90" part of the name refers to the setting time, in minutes. There are other times available, but, for this kind of work, longer is usually better. I use a large plastic tub to mix it in: I think mine was sold as a cat litterbox. Follow the mixing directions on the package. It comes in 5 or 10 lb. boxes or in more economical 35 lb. bags. Don't mix more than you can use in the allotted time, as this stuff will set regardless of how thin you make it. I use a wide scraper or putty knife to mix and apply it, and before it sets, use a cheap nylon paintbrush, dipped in water, to smooth out any trowelling marks. Depending on how thick you apply it, it may take several days to cure completely: if you need to carve in any type of rock detail, do it promptly, as once cured, this stuff is hard!
The excess material that dries in the mixing pan before it can be applied is useful as rip-rap for fill along the tracks, or as loose stone rubble at the base of a cliff. After it's put in place, spray it with a wash made from water-based paints, then fasten in place as you would ballast. I paint the plaster landforms with flat latex interior housepaint, thinned at least 50% with water, which soaks in better, is faster to apply, and makes the paint go farther, too. Don't thin the paint if you plan to apply ground cover while the paint is still wet, as the thinned paint soaks in almost immediately.
If your layout is on a plywood tabletop, spread some newspapers on the floor around the area where you're working. If your layout is on open benchwork, like most of mine, spread newspapers under the area where you'll be working, too.
And you're right about it being more fun, too!! :mrgreen: :mrgreen:
Wayne