2x volume or 1 volume and 1 blend controls?

[Cosmiceddie]

I prefer two volumes and a switch.

A 3-way switch or a toggle switch?

 

[bikeplate]

Master volume

 

[Korladis]

A 3-way switch or a toggle switch?

Three way switch. Though you could also make it a four way rotary with one position being no sound at all.

 

[Brad Johnson]

Having one volume knob is important to me.
If there is a song I'm not playing on I'll turn my volume down. When I turn it back up I want to have precisely the same blend I had before. I can't be sure I'm doing that with two volume knobs at different levels.
If the double volume knobs was important to me I would consider making one of them a pull/kill switch so I could mute myself without messing with my blend

This. VB for quick single control volume changes. VV with mute for turning everything off while maintaining volume settings.

Wish I had mutes on all of my basses. Really simplifies things live.