Best ways to make a suitable backdrop for a track

brown/green blankets would cover stuff
crumple some brown paper for rocks

and printed card for buildings is a good start

have fun, good luck

dr

When I first made the canyon, it was during lockdown so had to use what I had. I used a large brown duvet cover and some sheets, then some large sheets of paper (had a roll of packing paper luckily) that i crumpled up then opened back up and painted - looked surprisingly rock like - and the whole thing was made out of what I had at home. You can make simple fake buildings by printing out pictures of buildings and pasting them onto flat cardboard or onto small cardboard boxes and putting them in the background as well. 

For Possum Hills, I used some flooring board and painted it simply by puring some blue and white paint in random patterns then used a brush in one plane only, to give it a blue sky with a feel of light clouds int he sky. The ground in a lot of places was some brown material I bought that looked a bit like felt, then painted it with a couple of different greens in rattle cans and finally sprinkled some small flocking around it to break up the texture. All very simple and low cost and do the job.

Cardboard and spray paint 

I used a black burlap sack material. It was dirt cheap. It's see through with lights behind it, but I record at night so it's all black. I used a light blue sheet before, and that works well too. Like everyone said before, big sheets do great. 

A browse through the Track Directory should give you lots of ideas too. From simple to fancy, it's all there. But I'd say don't sweat trying to get too fancy, too soon. If anything just tidy up :) And then figure out what you can get away with.

I'm not able to set up a diorama,  but thought of getting a photography/ video meeting backdrop.  Sometimes they go fairly cheap.  Got the idea when work from home was less, and a friend offered me one free  (not for a track backdrop, just to get rid of it.).

Black table covers work well, if you hang them from the ceiling. You can also get blue ones and dot white clouds here and there on them with spray paint.

places sell backdrops for model rr layouts
not cheap, but some are super nice

I have used black and blue plastic table cloths  from the dollar store. They are pretty big, easy to cut, and cheap. They are thin, but you can double them up if needed. 

goodwill sells mismatched flat bedsheets pretty cheap...

I  have been moving lately and have a collection of u-haul packing "pads or blankets"... that were pretty cheap and thicker kind of rough textured felt like material. I plan on using it as the base cover but it would also work well for wall cover...