Everyone may need a different set of recommendations, but these few are a great place to start.
Avoid shoes that are too flexible in the middle. Wear shoes that have a stable midsole.
Replace old running shoes.
Temporary decrease training. Stop if necessary.
Carefully examine your training regimen. If you've been keeping a running diary - check it for possible training errors.
Since Iliotibial Band Syndrome seems to be caused in large part by hip abductor muscle weakness, it is vital to strengthen these muscles.
Perform hip tilts on a step or flat surface. Repeat 8-12 times each side.
Perform bridges 10-15 times. Do one to three sets.
After bridges become easier, add in 8-12 single leg bridges.
Gentle foam rolling with soft foam. Do not cause significant pain with foam rolling. The idea is to get better, not cause pain.
Additional core work if needed: Planks, side planks.
Hip flexor, hip adductor, and abductor stretches.
Calf muscle stretches.