Put something in their hands to remember you by.
No matter who your target audience is, a great way to be remembered is to give them something useful that they can carry out into their day to day.
A water bottle, a pen, a pill box or a carrying bag, these are useful and well used items that can carry your brand. Give them something to remember you by.
Students use pencils and pens everyday, and they tend to hold on to things that are useful like a water bottle or a planner. Any school supply can be a consistent brand reminder that is literally in their hands.