Look for a real limitation
A smaller board makes sense when you repeatedly reach the limits of your current board’s turning response, not when you are still missing waves or losing control during take-off. The problem should be visible in your surfing, not only in your ambition.
Check the foundations
Before changing, you should be able to paddle into waves without regular assistance, choose a workable line, stand with control and recover from ordinary mistakes. You do not need perfect technique, but the basics should survive when conditions are less than ideal.
Make the change measurable
Borrow, demo or test a board in familiar conditions where possible. Compare wave count, paddle fatigue, take-off success and the quality of your turns. Extra response is useful only when the rest of the session remains productive.
Use smaller steps
A moderate reduction helps identify what changed. A dramatic drop in length, width and volume creates several new problems at once, making it difficult to know whether the board is unsuitable or you simply need more time.