Having just completed Shrek The Musical Junior at our school, the biggest time consuming job was creating the backdrops. Having looked elsewhere to buy or rent backdrops, I was over whelmed with how expensive and not really creative they were.
So - I created them all myself with the knowledge I can sell them on for a much more affordable price for other educators. Most of backdrops are animated - you just simply need to loop them.
I hope this saves you loads of time.
If you have any issues, please reach out.
GBruce