I was using an sm58 until recently through Behringer MX pres. For months I coudn't get any "life" into the vox until I did four things:
1) really really crank the gainstaging in the board, run the "trim" control as high as you can, singing 3" off the mic and get it clipping at high points, then, rather than turning the trim down, sing a little further away to tame the clipping. Try not singing straight into the mic, but on a 45 degree angle across the capsule.
2) multiple passes of light compression, ratio of about 3:1, threshold -12, really short attack, longer release, gain of 4-5 dB.
this will bring much more life into the vocals but more noise.
3) I then manually clip out all the bits of the vocal track between words/phrases to eliminate any straight hiss (there is a lot when you record like this). Because if you don't do this, you will notice a noise floor of around -35 to -45 dB which really muddies up your sound. Immediately underneath vocals of -5-6 dB, however, you won't hear it as much.
4) then...and only then, after 1, 2 and 3, bounce all the little clips that you are left with back to a single clip, and then start farting around with some reverb to refill all the dead space you just cut out. But this time you are filling that space with vox, not Behringer hiss.
It will sound a little grainy, but it will sound much more vibrant.