It is important to try to maintain good circulation. When sitting for extended periods of time, you should put your feet up. Also, do not cross your legs, as this can restrict blood flow. At least 3 times a day, take 5 minutes to move your feet. For instance, wiggle your toes and move your ankles up, down, and around; all of these motions encourage the blood to flow to the feet and legs.
Another factor that may help with circulation is to abstain from smoking. Cigarette smoking has been linked to poor circulation to the extremities and also reduces the amount of oxygen in the blood. Overall, it is just not a conducive habit to have if you are already battling circulation issues.