What kinds of sketches do you draw?
Try to write pseudocode for the critical parts so you can test your design before you write code.
Try to write pseudocode for the critical parts so you can test your design before you write code.
Sometimes class diagram, sequence diagram, pseudocode, scribbling on piece of paper etc; whatever gets me going quickly.
I find OOP to be weak in the design stage. It does help later to simplify the code. But, only after you find out where the actual objects are. I prefer ERD for any modeling I might need in the design.
Older methods like structured design and data-structured design offer better guidence in the design stage. Too bad people look down on anything that is not OOP (or the newer hype FP).
The most useful method by far, however, is to recognize the shape of the problem, look for and apply a known solution.