Snare is the pulse of a rhythm section. It pumps movement into a song and supports the kick drum. However, the snare drum can be one of the more difficult sounds to mix. Snare is usually so prominent that it resides up front in the mix and usually sits right behind the vocals. So here are a few tips for good mixing techniques to get the snare in the pocket.
First, use good mic placement to capture the tone and ring of the snare that is desirable for the track. Typically a SM57 is used for snare tracking, but you may want to experiment with other mics to see if they give you a sound that is more desirable. I've used a Sennheiser e606 with great results for rock and punk snare recordings. Paired with the right preamp, you can really sculpt a tone that is your signature.
The next step is EQ. See if you can find the frequency that is prominent in the vocal track and then notch out just a touch of that frequency in the snare track. Also, use filters to help shape the tone of the snare so that it fits nicely into the mix with the other drum mics. As a sidenote, be sure to monitor your overhead mics as they will have plenty of snare sound. Sometimes there is a boxy sound to the snare around 300 Hz. Sweep your EQ around this frequency range and find the Boxee sound. Once you found the undesirable tone in the snare just notch it out a dB or two. This will help your snare cut through the mix and sit nicely behind the vocal track.