Leaving the appliance (and your work area) *cleaner* than it was before you arrived---is another win-win with the customer.

Quadruple check the refrigerator / dishwasher / washer water hoses---and at both ends. Even if you haven't touched them. Chances are someone else (before you arrived) has---and left the hose(s) only finger-tight.

A little movement of the appliance---and the hose begins to leak after a few cycles (or use of the appliance).

The sudden pressure build-up in a hose---when the valve closes---can spring a drip-drip-drip type leak.

Gas pipe connections---tighten 'em---leak test 'em. Check again. Replace the gas pipe when in doubt of it's overall condition.

Floors---wood or congoleum---notify the customer of any/all blemishes---the moment that you enter the kitchen or laundry room.

Most customers (in my area at least) are appreciative of a technician that demonstrates immediate *situational awareness*.

Not some guy plodding through their home in a "Mental Holiday" state-of-mind.

Lastly---if you *do* goof/screw-up---own up to it.

People are amazed when someone takes responsibility for their errors---they'll also likely continue to use your services---even if an insurance claim was required. Been there,done that.

Source: "Duh" repair follow ups and how to avoid them