Is your name Phil Spector, by any chance? Ha! I am just kidding!
Mr. Spector built a whole career with his "wall of sound" productions, but I'm assuming that is not the kind of sound you are trying to achieve. And that's just as well because...well it's not 1963!
Without hearing your mix, it's difficult to give a single concise answer, but I can throw a few ideas at you based on an experience I had within the last year. I recorded the basic tracks for an original song that seemed to call for a lot of instrumental parts going on at the same time. Then I added more tracks, and then even more. By the time I got my vocals recorded there was absolutely no more room! I spent hours and days trying to mix the song in a way that would make room for the vocals. Trying to do it all at once proved pointless; too many instruments competing to be heard. So I started over (mix-wise) by muting everything but the rhythm and bass. I paid close attention to the eq, reverb and any other effects. I also kept them at a low volume. That is very important when layering; you can always boost the master volume on the final mix.
Next I added the rhythm and ambient instruments, and mixed them as if this were the final mix, still giving each instrument a unique treatment. In one case I realized I had a track that wasn't even necessary, so I dumped it. It was an organ track, which wasn't really benefitting the song, but it was hogging up a lot of headroom. Then I moved on to lead tracks.
Did this solve my problem? Well, I can't say at this point because I'm still working on it. But it is flowing together much better.
I hope this example helps in some way. If not, just disregard!