A social system is not a grid of interchangeable templates. It is a visual grammar that makes a sequence feel related while allowing each post to have a reason to exist.
Choose the recurring signals
Decide what repeats: a crop logic, a colour relationship, a type scale, an object behaviour, or a compositional rhythm. Keep the list short enough that it can be used under pressure.
Give each post a role
Some posts introduce, some explain, some surprise, and some invite a response. The visual system should make these roles clearer, not flatten them into a single look.
Review the series, not only the frame
Look at the work together. A useful system creates consistency at a glance and variation when you stay with it.