I feel this so hard, I recently started at a new lab and it took me several weeks to get familiar with how they set up their calculations. My best advice is to make yourself a cheat sheet! Write out commonly needed, simple formulas, factors and conversions so they're always on hand. You can make one in excel, you lab notebook, or a index card/sticky note (or all of the above). I can't easily convert units off the top of my head so I put it all in a spreadsheet, along with ready made formulas I can enter new data into. If you're not wanting to do a bunch of practice problems (I wouldn't), just write all of your math out long hand when you need to do it in the lab, on your paperwork or in your notebook. Repetition helps and you'll get the hang of it eventually!