My views:
Well set up guitar ( which includes strings)
Good signal chain ( leads, buffers vs bypass if using external effects etc.)
Choose amps you already like and know - I have foudn I graviate to sounds I'm used to. I sold my ENGL to get a KPA using ENGL profiles ( yeah daft I know).
Test your sounds at full volume, with a band and via FRFR if going FOH. In other words closely mimic the live set up (if for live).
Care less about your tone - sound is important but 90% of our sound is from our hands and the only people in the audience really listening to your guitar tone are other guitarists...who won't like what you play regardless. Plus your ears/perception change constantly, even if you sound stays consistent
Avoid analysis paralysis - don't search for sonic nirvana, it leads to endless disappointment. Settle for 90%..
I rarely use eq, as said by others I tend to go for a good sounding profile and stick with it.