Bill, your story about measuring diagonals reminds me of the work when I was moving into this house I had the kitchen countertops and a new sink put into the existing cabinets. We also took out a hideous large furdown (drop ceiling) with florescent lights so needed new electrical connections for lights in the new higher ceiling and over the peninsula (a new light altogether). After the electrician came in and put in pots (junction boxes for heavier fixtures) before sheet rock was installed, I spoke to the carpenter and the countertop guys and asked if they could extend the far side out 12" to make an overhang that I could put tall stools under? Yes, that was easy enough to do.

When the electrician came out to install fixtures I saw him measure and measure again and scratch his head - then he turned to me and said "you changed the size of the counter!" Yes, I did, and I told him it was okay if the light was closer to the sink side of the peninsula. He'd made a point of centering it over the original counter.

I always have the electrician come out for major things like fixing shorted out plugs. Most recently, there was a loose junction box in the brick wall on my patio that was part of a GFCI circuit that was connected to both bathroom plugs, and I couldn't get any of those plugs to work any more. He changed out that j-box and used enough silicone gel to hold it into place for a long time. I love that I don't have to go flip a breaker on the junction box after a thunder storm any more.

I do the smaller stuff myself. I change out fixtures and switches, mostly. Small things possible by turning off the breaker serving that room doing the work by flashlight. If I called the electrician for those jobs I'd end up waiting a long time till I had enough to merit a service charge and would live without those switches or lights for a long time in the process.

(This isn't my kitchen but you can see the furdown with built-in florescent lights. My kitchen looked cave-like with that feature of 1976 home design, so I got rid of it.)