How do I design my own experiments instead of just following protocols?

Following a protocol and designing one are different skills, and having the first is exactly how you earn the second. Design feels overwhelming because a blank protocol has infinite choices. But good experiments all start from one narrow, answerable question. Begin with the question, not the method. What exactly do you want to know, and what result would prove it one way or the other? Once the question is sharp, the design gets simpler: what to change, what to hold steady, what to measure. Borrow structures from experiments you have run before instead of inventing from nothing. One small step: write your next experiment as a single testable question and the one comparison that would answer it. Build outward from that sentence.