I remember from a PEEL PD session in my first year about allowing student to come up with rules, definitions or generalizations to make it more meaningful and memorable.
One card sort I was inspired to create was types of Linear Functions. The idea is as a class (or small groups) students come up with ways of classifying the mix of linear graphs.
Yet to trial it, the aim is they come up with positive, negative, zero and undefined groups where we then can go back and formalize the definitions and connect it back with the rate of change.
Or watch the adventures of …..Slope Dude!!
Other card sorts: Similar and Congruent and Polynomials