" Showing units can be a pain because 50% of the time, tenants will not show up. To combat this, I use one of two techniques:
1.I give them the address to drive by first and tell them to call me back if they are interested in seeing the inside. This eliminates the people who are disinterested because of the location.
2.I try to “batch” all the showings to one time. I will tell all the callers that I will be at the house from “5:00 to 5:30 on Friday afternoon” and if they want to see it – show up then. Having multiple tenants look at a property at the same time can be a little bit awkward, but it creates a sense of competition and scarcity which allows for "

― Brandon Turner , A BiggerPockets Guide: How to Rent Your House