Don't test everything. Experimentation isn't about proving how clever you are. Mistakes in testing ideas from your own head are common; personal bias clouds results. High-performing experimentation needs executive buy-in and integrated roles. Successful teams engage diverse players with vested interest, ensuring hypotheses formation and metric selection are comprehensive. Valuable experimentation saves time by testing what not to do. Rather than just chasing conversion lifts, recognize when improvements won't make a difference. Cultural shifts, humility, and prioritizing efficient use of time are key components of effective experimentation programs. Test what makes sense.