A baby's suckling is always going to have more of an effect than a pump.  If you have a child who will suckle, get a Lact-Aid and offer the breast as much as the baby will take it.  As your milk supply builds you can remove your dependence on supplementation both by formula and the Lact-Aid.

Invest in a good hospital-grade pump.

Pump at least every 2 hours initially and if you see some milk production you could probably drop to every 2-3 hours.  For the first 4-6 weeks you must pump every 2-3 hours in order to see any results.

It generally takes at least 4-6 weeks to see any milk production - less if you have lactated before (and especially recently); more, perhaps, if you never have.

Be DEDICATED.  I know how hard it is and I know the dread of looking at the pump yet again in the day.  It is difficult, at best.  If you are going to do this, steel yourself to the downs of it and look forward to the flowing milk.  It is hard work but you can do it!

Research whether medication might help you - especially if you live outside of the United States.  Inside the United States the only medication your doctor can prescribe to help is called "Reglan".  It is not used for inducing lactation; however, it is a side effect of its intended use.  I have heard much praise about the use of Reglan in this regard; however, I have heard as much, if not more, cons about its side effects.  Be sure to follow the link below for an article regarding the use of Reglan and it's side effects.  If you are outside of the U.S., there is a medication called Domperidone which is supposed to be REMARKABLE at assisting with induced lactation.  It is not prescribable in the U.S. although I've been told you can mail order it from a pharmacy in Mexico (hint: search the web.