We made a large round sign out of the bag the sunshade folded down into and attached it with cable ties to the handles of our mac, it needed to be cut off to get it off. It doubled as a pocket to keep stuff in.
It was around 15inches diametre and we put "W****** Family" in HUGE bright pink letters on it and then we wrote our resort name (All star movies) and room number on it too, that way we figured if it got moved and we couldn't find it and was cleared by CMs at the end of the park day it'd get sent back to us or we'd get a call to collect it.
It made it easy to find- some of the stroller parks in busy areas (like outside philharmagic, outside buzz light year) had 50-100 strollers in when we went (august)
Our stroller DID get moved one night, every other time it got moved within the same stroller parking area and so we just looked there but coming out of the laugh floor it had been moved to a different stroller park (outside the back of the stitch ride) and it took us a long time to find it, if it would have been unmarked I may well have missed it and assumed it was stolen.