Be sure to use pillows with this position so that you can be sure that the baby is well supported. If the baby is longer than the space you have between you and where you are sitting, bend the legs upward, so that their bottom is against the back of the chair or bed. This prevents you from leaning out.
With this position you can also use the other hand to help better position the baby's mouth or your breast. It gives you a great look at the breast while nursing, so works well if you're having latch issues.
Photo © Robin Elise Weiss