Well John,
I would first experiment with putting more distance between your amp and the other guitar amp. Angle them toward the audience at slightly different angles. Now days most bands use a master board and have a person to keep the volume of each player adjusted and properly mixed. Many bands could not afford to do that as was my band many years ago.

We just spread out as much as possible and experimented and we worked very hard on two things, of course timing, and the other biggie was volume balance. We always kept working on balance of volume so that some was not louder or softer than others. For lead guitar you need a volume pedalto foot control your volume boost at solo times. Each place you play at will be a little different so you may want to log your shows and keep track of the bad things and the good things that went down there at that place.

Eventually you will get the hang of it. Now I will be brave and go ahead and say this . . . I personally prefer the band to play without the aid of the mixer board. Many would say I'm crazy but I've done it both ways and the band who does not use that board has to work much harder to achieve a good true balance right? Here is why I say this. After working and practicing and working and practising so much to achieve good balance without any aid of a mixer board, we became so good at it when we went into the studio to do a session at the old original Oak Ridge Boy's studio, the engineer stated that he could hardly believe how so well balanced we all were and that we were the best most professionally balanced band he had ever had the pleasure to record.

He said it was so easy for him. He had never heard such smooth natural balance. very little sdjustment for him on the tracks he recorded. He asked how did we manage and we just told him we forced ourselves to work so hard at this and we did not use the mixer balance board. It made our natural balance far ahead of most bands.

Also when using a board you are still up to the mercy of the guy who controls it, how good is his ear makes a big difference. We had nmore mental trelepathy going on than any other group I played with ever and that was the only band that thought this way and worked thais way.

Hmmmmm, it worked and proved itself and impressed the socks off people how balanced we were with no other help but our own ears. The really hard places are such as gymnasiums with all the echo going on but we got there eventually and finally learned what rules to apply in what conditions. It worked extrememly well for us but it took a lot of work on everyone's part working togtehr as a team. Well, I guess dat be enough out of me for now.

Hope this helps you.