You all probably know this, but I'd never heard it.
Raise level of cooling rack by placing it on four inverted teacups. I
tried it last night and my blueberry muffins cooled faster and had a
nice crust.

I also attribute the crust to the oven thermo I finally bought. My
oven was beeping as preheated and it was a good fifty degrees below
the setting. I shall now take that beep as just a five minute
warning.

I also went back to the muffin tins which are NOT the non-stick. It
soaked all night in the sink, but I've decided ease of cleanup is
sometimes not worth it for the final cooked product. I think the
nonstick pan is Goodwill bound.