In a bar of triplets in * time, there are 12 different positions for notes within the bar. The first beat is 1, the middle note of the first triplet is called the "trip of one" and the third note of the first triplet is called the "let of one". The system then continues through the bar – 2, trip of 2, let of 2, etc.
It is worth practicing your bass drum on each of these positions until you can do them at will. When playing this example, count the bass drum hits louder than the other notes. The right hand plays all the notes of each triplet here to help you keep good time.
Here are some common drum beats based on triplets. Try creating some variations of your own by experimenting with different placements of the bass drum.