Most trades are licensed through a state governmental agency such as a "home improvement commission". You'll need to find the agency in your state and verify that the tradesmen is, in fact, licensed and in good standing.
Is the majority of your work in repairs,remodeling or new construction?
The point of this question is legitimacy. A pick up truck is not an acceptable answer. You want an established professional who takes his business seriously.
Tradesmen such as electricians can quote prices in three distinct ways:\0121. Time and Material - an hourly rate plus the cost of the materials (which may be marked up).\0122. Flat rate - e.g. installing a receptacle costs $75. \0123. Bid - tradesman provides a comprehensive quote upfront for what the charges will be which includes all labor and material charges.