When playing the marching bass drum, your forearms should be parallel to the ground, bent at the elbows. The line between your shoulder and elbow should be vertical. Hold the mallet upward at a 45-degree angle. Adjust the carrier so that the heads of your mallets will strike the center of the bass drum. The adjustments you make to the carrier will differ depending on the size of the bass drum you're assigned to use. This position should feel relaxed.
If you feel uncomfortable, or if your knuckles hit the hoop when you strike the drum, try adjusting the carrier further. If you're still in an awkward position, it may be necessary to try a larger or smaller bass drum. Comfort is paramount; you'll be carrying a rather heavy instrument for long periods of time, and fatigue will reduce your enjoyment as well as the quality of your playing. You should feel like the drum is being supported by your back and core, not by your neck and shoulders.
To hit the bass drum, movement should be made with your forearms, not your wrists. Use the weight of the mallet heads to help achieve a good feel. This will attain maximum playing power and assist with required dynamics changes. Playing by moving only your wrists will result in a weaker sound and will quickly fatigue the player. Your mallet technique should generally be legato, unless the music calls for a different style.
Most marching band music includes polyphonic bass drum parts, often with four bass drums. For this reason, it's very useful to practice the music with all bass drummers present. Listen to your fellow drum line members. The sound queues they provide will help you to learn your own part. Accuracy among the bass drums will be very important to the sound of the entire drum line, and to the band as a whole. A sloppy bass drum section will generally result in a sloppy band. Bass drum notation can often be alternatively sparse and dense. For this reason, it can be useful to circle your notes or sections of notes when practicing alone.
Keep your drum in tune. Smaller bass drums should produce higher notes than larger bass drums. Remember to properly care for your bass drum. Storing it in a hard shell case in a cool, dry place will prevent common issues such as scratches and detuning.