How do you add a new instrument to only one area/one part of sheet?

So I'm compiling a bunch of riffs that sound good and I plan to use in the future, but some of them are for different instruments, like guitar, bass, shamisen, etc., and I want to be able to write them in their own instrument staff, but the vast majority of the riffs are just guitar, so I don't want to have two extra instrument staffs taking up three times the space when they're mostly going to just be blank. So can I only add an instrument staff under one row of bars?