Profile your amps, modellers, software modellers ... by this we learn a lot of the other gear and the KPA.
Don't be afraid to create your own profiles - yes, even the cheapest mic with the right placement can create great sounds.
You don't own great tube amps - maybe a friend does?
Sometimes even cheap amps - combined with large speakers can create a HUGE sound.
e.g.
This are profiles of a very small Roland Micro Cube Amp amplified with a studio amp and then played via a MesaBoogie close back C90 cabinet - recorded with a R121.
This strange combination of a $100 amp and additional gear for about $2000 creates this great sounds.