A name of a rudiment which you may have heard before but you're not really sure what it is, is called a flam. A flam starts out with one of your hands or arms up in the air, and the other one as close to the snare as you possibly can get it, and it's going to be what's called a grace note, it's going to fall right next to your main note.
The objective of this is to do a normal full stroke, and to land your upper hand on the down beat, or on the number you're counting, with the other hand throwing in a little tiny grace note right before that, right as you're striking the other hand. Now the most important thing about a flam is the setup, or what I mean by setup is to get your hands in the right position first before you strike it, and that would be one hand up, and the other hand close to the drum as I mentioned, and this is what we call a right flam, with the right stick up and the left stick closer to the drum.
When you play it, you want to basically set these down as close as you can to each other without hitting them exactly at the same time. It sounds like this. Now it's important to understand that flams alternate, so after you strike a right flam, your hands will reverse themselves, your right hand will start up high, you'll strike, and everything will reverse for your left hand that will become high, and the right stick is back towards snare drum head. It will sound like this. As I mentioned, the most important part of the flam is the setup, and you want to make sure that they're either not too separated, or too close to each other where they land right on top of each other.
Remember, as you alternate, make sure your sticks reverse themselves, and go for that even sound on either side of your body.