Lymph is a clear fluid that resides in the space between cells in the body, and is transported by the Lymphatic system, a system of vessels that are as extensive as the circulatory system. The Lymphatic system is essential for immune response and nutrition, as it acts to transfer fluids between cells and organs, as well as deliver contaminants to the lymph nodes, where they can be isolated and destroyed.
Lymph is created when the interstitial fluid between the cells is absorbed into lymph vessels, where it combines with nutrients and white blood cells. The lymph flows all around the body, collecting and discarding nutrients and contaminants, and eventually mixes with blood in the subclavian veins. Lymphocyte levels in the blood is measured with the White Blood Cell Differential Count test, and can be a sign of problems with circulation or immune response.
Strictly speaking, there is no way to "increase" lymph counts in the blood, since it is monitored and regulated by the body's natural process. Exercise can increase lymphatic activity in the blood, allowing more transportation, but you cannot take a pill or use massage to "create more" lymph. Besides, you don't want to much lymph in the blood, because it can cause problems with immune response and clotting. Healthier living will help stabilize the lymphatic system; you always want your lymph levels in balance, not high or low. A healthy diet and daily exercise will do more for the balance of lymph than most "alternative" solutions. See your doctor for a WBC Differential Count, increase vegetable and fruit servings, and take up yoga or other low-impact exercises to begin with.