Monthly Rental Increase Strategies

[Chad Jarrah]

Hey all, had a question that's been nagging me and wanted to get some thoughts.

I'd like to hear how investors increase monthly rents (residential) to their tenants. Do you have a percentage increase every year built into the lease? Just raise it a certain dollar amount every other year? Only raise it when a tenant leaves and a new tenant is on the way? Do you have renter's pay the water/sewer bill?

I have 4 rental props but I never quite figured out a good system for raising the rent. 

Thanks in advance!