A question for you sound pros

So, my band lost a guitarist, and now are bass, drums, and just one guitar. This kind of leaves some "empty space" in some songs where I would rather have more of a wall of sound. Any tips that might help me fill that space up? I also, of course, don't want to combine my sound with the guitarist. So far, since he makes the smiley face EQ pattern, I do the opposite. I play through either a Gallien-Krueger 1001rb and a 4x10 cabinet, or a Peavy 80 watt solid-state combo amp, 1x15, depending on the practice space. I know it would be impossible to make a solution common to both amps. But, how can I make more of a wall of sound sometimes, beyond just EQing correctly?

Will take any and all advice, thanks guys!

 

I forgot to add, I play drop D, and so does the guitar. I am not too big on using effects usually, I like a more Ryan Martinie style of using octaves and stuff with my hands, but I suppose I could give it a shot. Would maybe a overdrive or fuzz pedal work, as long as I dial it in right? Or should I stick with a more clean tone paired with some kind of effects pedal? Sorry for my lack of knowledge, I just usually liked a clean tone, but I really want to thicken up the sound a bit in places.