Lately I've been trying to mix everything lower, but volume levels creep up over time. Usually I'll write a song that ends up around the A level, but I like to drop my entire Wave channel down to Volume 2 so that the kicks stand out a lot (at 3); this means I basically go through the entire song again after I've written it and bring all the volume levels down as much as I can. I wrestle back and forth with it a lot.
Also, when you're making your Wave instruments try changing the volume in the synth screen to 80, it boosts the whole thing up.