Wondering what peoples favorite mohair or alpaca cinches are. Also, what's the best way to keep them soft/clean? Thanks!

I know of several people that make them so I tend to order from them. But I've had a few of the Classic Equine ones too, no issues.

They do tend to stretch some so I order mine a size smaller. Remember that as well as your using it for the first couple of times. You might have to check your cinch a few times during your ride. Same for after you wash them.

 Washing in a bucket with a little bit of Dawn dishsoap or Woolite works good.

I really like the Jeremiah Watts mohair cinch by Weaver.  They give and stretch as needed when it is on the horse but goes back to normal off the horse and they shake out super well.

I've been really happy with my Toklat flex form roper cinch. It's wool though.  It's used daily on 2 horses and it's held up great. 

I currently have a Toklat T3 Flex Woolback. I do like it, but the wool is getting pushed back to the nylon(?) from my horses shoulder. My cinch sits a bit far forward d/t her conformation. I tried the Shoulder Relief Cinch, but that worked terrible for her. So I'm thinking a string cinch now because its soft and flatter. Hoping it doesn't get in her way. 

I'd stay away from the roper style and try a straight cinch as well as a string cinch to reduce the bulk being pulled into the armpits/elbows.