In terms of a guitar amp,I would do the same as a stereo amp,up the treble and down the bass,treble equals clarity to me but I don`t over do it,sometimes it gets too tinny.
My headphones are really bass heavy so I have to cut the bass down anyway.
I like the Nirvana suggestion,thanks to Uma`s Cow for mentioning that.
I know Pavement had that treble kicker tag in the early days,they did`nt have a bass player either.
In terms of bands without a bass player:Spinanes,Sleater Kinney,Jon Spencer,early Modest Mouse(early recordings had just Isaac and Jeremiah),Beat Happening,and sometimes Yo La Tengo(when Georgia plays guitar and James plays drums) and Silkworm(when Tim plays guitar instead of bass) all proved that it can be done.