Pay. Pay pay pay. I have verified this across four years, two different positions, and through friends in HR: the salary you negotiate when you first start working here determines your salary range throughout your career unless you're very aggressive about seeking promotions. I was a data tech II for three years and then got what is technically a promotion to clinical trials assistant II at a different lab, and due to "funding constraints" (i.e., PIs never want to spend their grant money on fair salaries and the department takes their cues from the PI) all they did was meet what I was making at the previous position. I regret not pushing back on that, but when a PI says they don't want to pay you more, and the DUHS HR metrics are skewed to be as conservative as possible, there's not much anyone wants to do about it.
Raises outside of promotions are very rare (outside of the oh-so-generous <2% cost of living raise each year.) And promotions are quite difficult to finagle unless you earn a new degree/certification. Getting acknowledgement for experience or a job well done does not happen on its own here. So my advice: go as high as you possibly can when you first get hired!
