You can’t instantly just be a better dancer. It would be so nice if you could, but unfortunately that’s not the case. With that being said, relaxing your upper body so you aren’t stiff (this is something beginner dancers typically struggle with since they’re so focused on remembering steps and their lower bodies). If you’re doing ballet/contemporary/modern, keep breath in your arms, elbows lifted and arms held from your back. Use your eyes to direct the audience where to look and be expressive. Passion/expression is something that is difficult to teach, so if whoever you are trying to impress sees that you have that passion/expression, it will not go unnoticed and will make you appear to be a more mature dancer. Hope that helps!