For most hand drums, hitting the edge of the drum with the knuckly part of your palm and letting your fingers bounce off the head gives you the best basic open tone (this stroke puts your fingers about 4 inches in from the edge of the drum). Experiment by moving your fingers closer to the center or the edge and see how the sound changes. You want a sound that’s rich, clear, and without any overtones (those annoying ringing sounds that get in the way of the clear tone).
Every drum sounds a little different depending on the diameter, tension, and thickness of the head. Thinner heads tend to create more overtones than thicker heads. You may need to move your fingers closer to the center of the head to get the best quality sound. When you find the best spot, practice hitting it a while and get used to how it feels.