I use a few methods
on My Giant DH
well this Downhill bikes Do crash a lot and more than a lot they crash Really, ReaLLY hard, so a nice strong protector is a good thing to have, also the chain is prone to hit the "seat stay" so i made a double guard,,,,,
can you say totally quiet
I love my Ritchey WCS tyre and I was really sad to see her go,,,,, but as a chainstay frame protector is pretty cool
I don't know if you can see but the guard is "Shoe lace" to the frame ussing nylon cord like on a shoe or even better a fancy corset
On MY Nicolai M-Pire the lower chain stay guard is made of "seft vulcanazing" tape that you can find a fancy boat shops,,,
Amazing stuff super strong and very rubber like,, in fact becomes a whole unit after a few hours after the you rap it
actually take a look at the "Seat stay" guards, the nicolai's are super wide at the rear dropouts, with a 165MM hub and rectuangular chain stays you heals end up hitting on the seat stay all the time so I made this thermoplastic carbon guards by hand to protect the finish and the longetivy of the frame
same Vulcanize tape on my Azonic saber.
if you need something narrow, durable and self adhesive this is the best
and then for the rest of the Bikes i use Recycle tyre liners
Actually this are my Favorite chainstay guards, I use the material from the "Mister Tuffy" whatever useless tyre strips, but they make for the best Chain guard material since the are flexible strechable (some of them,,, the ones I like at least) and super dupper resistent to cuts and abrations...
plus you get sufficient material for two bikes for every tyre strip..
here is on my Chalelon
and here is the protector On my little balfa
Here the two bikes after a nice day of riding