The first thing with a snare is that it's very much the transient that's hitting in: you want it to be really fast and sharp. You can lose that quite a lot in mastering. It's important to be between what you're doing so that you don't lose what the mix engineer or producer has done with their snare.
It's key to get that snare heavy in the lower part so that it gets that hard whack with some EQ. Make sure the compression isn't too tight. If you're using something like a mastering and SSL compressor, it'll sound very nice because the little tracks are all glued down. But then you switch it between the A and the B, and you've lost that kind of sharpness and that space within the instrumentation, especially with the snare.
One of the things I'm always listening to is how that snare's hitting; if it's hitting all the way through. Because that's something that people hear subconsciously, and they're noticing. They might not think that's the snare, but that's the thing that's keeping the groove going. If you want to pull the snare out a little bit, then put it around the mids – around 2.4K – and open it up with a cue, to hear what's going on. You can start making it sound hard, so it's getting a balance between being hard and soft. You need to use an EQ that's not too brittle to do that.
Using a brittle EQ gets you that hard thing, which is also quite nice. If you haven't got a vocal over the top, then that hardness can work all right because it's going to give you a nice edge. But it's a problem if you do: the vocal is what the majority of people listen to. The vocal is the track, so if it changes, that changes the style and the sound of the song more than the snare is going to.
It really is a question of whether you need to bring it out. But what works for me is to make sure that I'm not compressing too much. It's the snare that brings out some edge in the mid-range. If you start pushing into the compressors or limiters, then they're going to make it sound crushed. You're going to lose that snap transience on there, and end up with a track that's a bit flat and not edgy enough.