I agree with the "troublesome customer don't bother to show up" thing.

Some people are *never* satisfied with your work and will complain about
anything and everything. They want you to do the work for below cost, then
expect perfection and top quality.

I know a couple of women that I will never do any work for. I have seen
these people complain about every single bit of work *anyone* has ever done
for them.

If I have to do any work in these situations, the price goes WAY up!
(Additional stress and grief fees!)

The opposite is true. If someone is nice to me, offers me water/soda, use of
their bathroom, maybe a snack, the price goes down. With some of these
people, they get free or reduced price service.

Another situation I will avoid is doing any work on manufactured houses.
Always a royal pain. So I am too busy when anyone wants work on their
manufactured home done.