2 instruments in the same staff?

Sorry if this has been explained before. I couldnt find anything that would help me.
I'm writing a percussion score for a marching band front ensemble. Each marimba, vibraphone, and xylophone player has suspended cymbals, wind chimes, crotales, and a host of other instruments that they also play. How can i add 2 (or more) instruments to the same score? (ie; suspended cymbal and marimba)

Thanks!