Supination/Rotation
For those struggling at home with no weights or access to a gym the best way to get a workout is to combine multiple exercises or motions into one.  This can decrease workout time while increasing the intensity of the workout.  Supination is a term used to describe a type of rotation involving the hand or the foot. When the term is applied to the hand, it describes the movement of the arm and hand that results in an upward-facing palm. When applied to the foot, the term refers to movement that results in the upward positioning of the sole of the foot. If the foot is supinated, the outer edge of the sole is used to carry the weight of the body.
Hammer/Bicep curl- Instead of gripping the dumbbell handle in the middle (as is normally taught), grip the handle with the thumb and forefinger side of your hand pressed up against the inside of the dumbbell plates. There will be a space of several inches between your pinky and the other side plates ( If this is too difficult then slide back to the middle until more intensity is needed.)  To take full advantage of this change in your grip, start the bicep curl with your palms facing in to your thighs, otherwise known as a neutral or hammer grip. As you curl up, rotate your forearm so that your palm is facing up at the top of the movement. You should feel a strong cramping in your biceps and in turn working more of the muscle mass of the bicep and giving you a stronger contraction. Holding the dumbbell off-center essentially adds resistance to the supination function of the bicep muscle. If you think about it, when you hold your hand in the middle of the dumbbell, the two ends are balanced like two identical-weight people on a see-saw. You get very little, if any, resistance on the supination.
Arnold Press-this is a classic bodybuilding exercise actually invented by Arnold himself, hence the name.  You start with the dumbbells chest high with palms facing your chest.  As you press upwards rotate the dumbbell so when you finish above your head your palms will be facing away. 
Dumbbell Rotation Rows-This is a favorite of mine.  Bend over or lay on an incline bench.  Start with your arms hanging all the way to the floor with your palms facing your toes.  As you pull both dumbbells to your chest rotate them so your palms will be facing your chin.  This one you will really feel in your biceps and back.