Listen to several recorded reggae tunes and, if possible with your software, isolate the drum audio tracks. Analyze what the drummer is doing with each piece of the drumset, including the snare, bass drum, hi-hats, toms and other cymbals. Traditionally, the emphasis in reggae music is on beat three, with a slightly "swung" feel to the beat. The swing in reggae means rhythms are played closer to a shuffle feel rather than straight rock. You may hear both the snare and bass on beat three with nothing on beat one (known as the One Drop beat), an emphasis on both beats one and three (known as the Rockers beat), and the more driving Steppers beat in which the bass drum plays on all four beats while the snare is on beat three.
Add your bass and snare beats first, creating a basic loop you can adjust and add to later. In order to be considered reggae, there must be an emphasis on beat 3, but feel free to be creative outside of that rule. For example, create your own version of One Drop with nothing on beat one, the bass drum on beats two and four, and the snare on beat three.
Add the hi-hat track. The hi-hat will typically utilize eighth notes and is therefore essential in setting up the slightly swung feel to the beat. However, you can break up the rhythm and add open sizzles for variety in your reggae beat.
Loop four measures of the three tracks you have created together and listen to it several times, getting a feel for the basic reggae beat you have created. Add other sounds and effects as you hear them, including other cymbals, bongos, congas, timbales, claves, cowbells and shakers. Give any extra instrument you add its own basic beat on one track.
Add hits and fills to your beat, which will typically come every four, eight, 16 or 32 measures. Fills are short "solos" that break away from the beat and typically feature just a few instruments, while hits are the release of tension after the fill. For example, on the eighth measure, write a timbale fill, then on beat one of the ninth measure, insert a crash cymbal hit on beat one before going back into the beat.