Seeking Advice: Building a Pricing Strategy and Ideal Customer Avatar for MTAC Plumbing

It really depends on your customer base.

For strict residential service work often we find flat rate to be best, as it makes it easier for our office and techs in the field to quote work on the spot themselves and makes invoicing much easier. 

For our contract work with larger customers it is usually T&M. They know our hourly rate and understand that jobs in larger buildings require more than a simple quick fix.