That's such a smart move! I started adding a line asking for a quick testimonial if they're happy with the work. It often turns into them bringing up the next small thing they need.

Guess my kitchen will look like a toddler's art project now. What's your color for the junk drawer?

What temp setting did you use on the heat gun?

Oh man, that's a rough way to find out. Worms actually breathe through their skin, so they need it to stay moist. When they're in water, they can't get air and basically drown, even though it looks like they're swimming. It's more like they're panicking and trying to get out. Poor little guys.

Works for me, but there are other ways too.