Sign up for a dance class specific to the R&B dances you want to learn. Some instructors specialize in smoother, slower tempo R&B dances while others teach more up-tempo routines. The aerobic and choreographic instruction of a dance class makes for an ideal environment in which to learn R&B dance philosophy as well as steps.
Observe and study the R&B dance you want to learn if you are not able to attend a dance class. Watch others perform the dance live or study recorded performances. Do your best to memorize the dancers' motions. Music videos can be acceptable R&B dance step templates as well.
Replicate your desired R&B dance steps in private in front of a full-length mirror. Play R&B music of an appropriate tempo. Use the mirror to monitor your movements closely, making sure they are in line with those of your template.
Rehearse your routine as often as possible until the R&B dance steps resemble those of the experienced dancers you replicate.
Try your carefully rehearsed routine at a disco, nightclub or otherwise public venue for R&B dancing. Be sure to add your own style and flair to the R&B dance step templates you have learned. Have fun!