How do you dial in the FOH sound? Do you run a wireless receiver? Then a lot of walking back and forth and tweaking? I've thought of that but I'd barely be able to past the front of the stage (plus a drop to the floor) even with a 18ft cable.
One of two ways. A wireless receiver or I have someone else play my bass/pedalboard (we have a few guys on the team that play bass well enough) while I listen out front.
Over time, I have also learned the room and our speaker set up. For example, our room accentuates ~2500kHz. So if I introduce a new amp sim on my Stomp or I am dialing in a new setting on an EQ/Preamp pedal (Silver Deluxe/SV-Pre/Super Stack/etc.), I know to be careful with 2500kHz. I also know that the engineer runs a HPF at 50Hz on the bass channel so I adjust accordingly. So forth and so on.
Also, we have a good sound guy whose opinion I respect. So I ask him, especially on rehearsal days, to listen specifically to the bass here and there and provide constructive criticism. Is my bass cutting through too much? Not enough? Are the lows (sub 500hZ) too overwhelming? Not enough? At first there was a lot of conversation, but again, through time and practice, I know what he is looking for, I know how the room will react, I know how the room changes when it is filled with warm bodies, I know how the speakers roll off certain frequencies, etc.
In addition, we have the luxury at our church to have live recordings. So I can go back and listen the next day and analyze which helps a bunch. Of course, the live recordings are the "direct to board" sound so it doesnt take in to account PA speakers or the room being filled, however, it tells me exactly what our online viewers are hearing and how my set up interacts with the sound guy's board mix (pre PA).
Nowadays, there really isn't a lot of back and forth because I have it largely dialed in. The initial time I set up a new pedal or amp sim, sure, there is some back and forth to get things right, but with my knowledge of the room and feedback from the sound guy, it only takes a few minutes really.