When most people think of kick drums, they imagine thumping low-frequency tones. After all, the kick drum is often referred to as the "bass" drum, and bass guitar performances hinge on the action of the kick drum more than any other percussive element. In reality, the sound of a kick drum registers across the entire frequency spectrum. While the low-frequencies provide the percussive propulsion, the snappy high-frequencies give the drum presence. Most headphones have poor low-frequency response, so it can be difficult to hear when a kick drum is EQ'd just right. Knowing which frequencies are "good" is a step in the right direction. A +3.5 decibel boost at 99 Hz will provide the thump, while a +4 boost at 5.33 kHz will provide adequate presence.
The snare drum also has surprising sonic properties. As the drum kit's "snap," unexperienced mixing engineers commonly apply hard high-pass filters to snare drums that eliminate the bottom half of the frequency spectrum. This removes the warmth and thump from the snare drum, and results in a thin, weak drum sound. A +1.5 decibel boost at the 177 Hz will unearth a lot of usable frequencies, while an immediate -0.5 decibel cut between 500 Hz and 1 kHz will keep the low frequencies from diluting the snare's snappiness.
The rest of the kit falls into place a little easier. The tom drums require few boosts or cuts, unless you have a particularly resonant collection of drums. In that case, a -7.5 decibel cut at 667 Hz will create a long decay, while a -9.0 decibel cut at 88Hz will emphasize the tom drums' punchiness. Headphones' poor low-frequency response is less of an issue with tom drums because the low frequencies tend to be eliminated to make room for the kick drum.
Overhead microphones can be tricky to equalize properly because they gather a little bit of sonic information from each piece of the drum kit. Some engineers overcomplicate the process by applying hard high-pass filters, eliminating low frequencies created by the kick drum and achieving more cymbal clarity. The same effect is achieved by applying a light +3 decibel boost at 13.4 kHz.