solid state amps matched with tube pre amp

Yes, don't ever turn you pre-amp on with your power amp already on.

I know my Herron VTSP-1A/166 pre-amp can be left on all of the time without prematurely burning out the tubes.

I believe the concern about that concers power amps rather than pre-amps.

I've mistakenly turned my pre off twice while the amp was still on and both times blew the fuses for both channels of the amp. I always turn the pre on first...let it warm up for about 30 secs and also make sure the 'Mute' is on , then power on the amp. When turning the system off I hit the 'Mute' on the pre first, then turn the amp off and wait about 20 secs for the caps to discharge, then turn the pre off.

Absolutely turn off the amp before the preamp goes off and and turn the preamp on before the amp...

I've had the UV paired with various solid state amps, and the results of turning off the preamp while the amps were on resulted in anything from triggering the protection mechanisms to blowing fuses. Not cool.

I would turn on the preamp then your amp and never turn them off until you need to swap tubes or your amp quits, IMHO. Your ears will thank you.