Squat with an overhead press: Start with your dumbbells by your sides, squat down and return to standing, pressing your DB's all the way up over your head. Repeat.
Alternating lunges with a bicep curl: Start standing with your dumbbells by your sides, lunge backward and step together while curling to the front. Repeat on the other leg, curling to the front again.
Squats with a bent over row: Squat down with your dumbbells by your sides, return to standing and flatten your back out with a slight bend in your knees. Row your elbows back as if to touch them behind you. Be sure to keep your core/abs very tight to support your lower back.