The snare is probably the most important instrument in the contemporary drums, it's mandatory to have a good sounding snare to have a good sounding mix!
At the same time the snare is one of the hardest instrument to eq without feeling "guilty" since it occupies almost every frequncy in the spectrum and for this reason we must cut something from it to make room for the kick, the bass, the voice and every other instrument that sits in the central position of the stereo landscape.
We start cutting from the snare every frequency occupied by the snare filtering out each frequency below 100-200Hz, the exact frequency is decided by your taste, if you want a thin snare use a high frequency, if you want a fat snare use a low one.
Another important part is the one that is between 2000 and 5000Hz, in this range there is the typical resonance of the snare, the tone you hear the most, usually we use an eq with a very narrow Q with high gain, then with the frequency control find the spot where the snare "sound good". Now lower the gain to a value between 3 or 6db, don't overdo it unless you want to make the snare sound different from reality! the go gentle on the q till it sounds good to you.
The high part is very easy, you just need to apply a boost above 8KHz to give more breath, dont' use more than 6db, for me the sweet value is 3-4db.
the compressor need to be set similar to the kick one, ratio 5, attack 15-25ms, release 1-5ms, compress to obtain about 6-8db of gain reduction, the using the gain control of you compressor set the level of the snare tail, the lowest the gain the lowest the tail, the more "dry" is the sound, easy enogh! :)
The snare is one of the instrument that gain most from a beautiful reverb, so don't be shy, but don't oveuse it unless you want to reach that 80s sound.