Design a sketch in an object-oriented fashion.
You might follow these steps and see how far you get. Even just doing the first couple of steps is okay!
1. Make one single object with just variables.
2. Put one or more functions in the object.
3. Try manually making two objects.
4. Duplicate the object using a for loop and an array to make as many as you like!
If you are already working with classes/objects and arrays, re-organize your classes into the "smallest functional units" possible (e.g. make properties in your classes that are functions, also called methods).
Try different ways to have your objects "communicate" with each other in some way.
In the end, the goal is to have code in draw() that only makes calls to objects.