Start bottle-feeding at least two weeks before your start date. Since breastfeeding takes more effort for your baby than bottle-feeding, start with a low-flow nipple to avoid overfeeding or breast refusal. Try offering her a bottle with a small amount of breast milk right after one of her feedings so she can get used to the nipple. Also, have someone else feed her — your baby knows your scent and will likely want your breast instead of the bottle if you are the one offering the bottle.
Talk to your employer before you return to work to determine where you will pump, and discuss how it will affect your schedule. An ideal space will have an electrical outlet, a comfortable chair, a table, a door with a lock, and shades if there are any windows in the room. Having a plan before your first day back will make pumping much easier.
If you can afford it, keep a pump at home and another at work to avoid having to carry it back and forth to the office every day. If having two pumps isn't an option, double up on the parts that need to be washed after every use so you'll have a backup in case you don't have time to wash them immediately after pumping.
Prints and loose-fitting tops work well to hide leaks and spills. Keep an extra shirt, bra, and breast pads at work for back-up in case you need to change.
Pump as often as you can. A good rule of thumb to follow is to do it whenever your baby normally eats. If there are days when you don't have time to get in your full sessions, try to pump for at least a few minutes. Skipping a session will not only make your milk supply dwindle, it can also make you engorged and put you at risk for mastitis.
If you find your production is low, consider talking to your doctor about taking herbal supplements that may help.