1) Too much signal? Stick a resistor in series with your volume control. E.g., a 47k resistor in series with the input to the volume control (assuming it is a 250k pot) will make the pot behave as if it is a 300k pot turned down a bit. You get to keep the full rotation of the pot, and lose some of the unwanted overdrive.
 
2) Too harsh? Stick a small value cap between the input and ground lugs of the volume pot to tame the high end. Something around 2200pf can do wonders for smoothing down the edge.
 
3) Too much bass? Stick a modest value cap in series with the input to the volume pot. Start with .05uf and work from there. Smaller values will roll off more bottom, larger will let more through.