"Break a leg" (theatrical)

This is a phrase that actors and musicians often use when talking to other actors and musicians before performing. It doesn't actually mean break you leg, it's just something to say to each other so that you don't say "good luck", because that can be bad luck on a stage. <br><br>So you would have to use something else instead. Let's say for example "May you have the best seat cushion on stage." Or "Getting your perfect chair is good luck".<br><br>What phrase would you use in a world building story to replace "break a leg"? If you could have anything be a stand in for that, what would you want?