power pumping tips!!!

Does anyone have tips on how to build a milk supply back up again? I'm still breastfeeding my 7 months olds but my freezer stash has gone down and I am hoping to go back to work and I'm already in school. I don't get super engorged anymore so I don't pump a lot. Does anyone have things that worked to build their supply back up and quickly build a freezer stash? THAN YOU (Also maybe some lactation pills that have worked for you)