Need Help

We started our pumping adventure 3 weeks ago when Lina was 5 days old, due to jaundice so severe she wouldn't wake at all. Going back & forth between NICU & home meant stretches of 6-8 hours between pumping sessions, which only further decreased my supply (added to stress, no sleep & eating once or maybe twice a day). We're back at home now, still continuing to supplement with formula (we had no choice, before you tell me to cut it out & put baby to breast), and I'm trying hard to continue with the pumping to give Lina whatever breastmilk I can produce. Hubby is away at the moment and will be for another fortnight, so I'm currently doing things on my own. I guess my question is, how do I get this pumping thing downpat so I can get things to improve? Throw me all of your tips, tricks & instructions - it's all welcome!