Here are a few drills and combinations I wrote on my Bellydance Willow Facebook page (http://www.facebook.com/bellydancewillow). All notation is written out and abbreviated in SS Format.
All Students - Work on isolating the upper and lower abdominal muscles separately. Just the upper - contract and release. Just the lower - contract and release. Then work on alternating the contractions between the upper and lower abdominal muscles, eventually smoothing it out into a belly roll.
B1 Students - Begin walking quarter time (1/4t) downbeat Right. Add alternating glute squeezes half time (1/2t) downbeat Right (DbR). You will do two glute squeezes (R L) for every step. When you are ready, increase the walking tempo to half time (1/2t) and the glute squeezes to full time (1/1t).
B2 Students - Walk 3 counts, Low Jazz Passe' on 4 (Walk23 Passe') Half Time (1/2t) downbeat right (DbR). Alternating glute squeezes full time (1/1t) downbeat right (DbR). Finger Cymbals 3's. When you feel comfortable with the alternating glute squeezes, change the bellydance move to twists. Everything else stays the same.
Layer Drill - Pas de Bourre' full time (1/1t) downbeat right (DbR). Twists full time (1/1t) downbeat left (DbL). Undulation Up to Down (UtD) half time (1/2t) downbeat upper back (DbUB). Finger Cymbals - 4 5 5.
Interval training is more effective than steady state aerobic activity. Short bursts of high intensity activity followed by short intervals of low intensity activity/recovery, rinse, repeat. Start incorporating bursts of Double Time Glute Squeezes with Double Time Footwork aka Running Shimmies, into your daily routine. You will develop your shimmies, glute and leg strength and increase your cardiovascular health!