Which action will not result in immediate demerits?

Wearing all recommended practice attire is a crucial aspect of drill team participation, as it promotes uniformity, discipline, and a professional appearance among team members. By adhering to the required attire guidelines, team members contribute positively to the team's image and demonstrate respect for the team's values and standards. This action is considered compliant with team expectations and standards, hence it does not warrant any immediate demerits.

On the other hand, using a phone during practice, allowing a non-team member into the locker room, and leaving food in the locker room are behaviors that can disrupt practice, compromise security, or create an unprofessional environment. Each of these actions is likely to be viewed negatively and can lead to demerits due to their potential impact on the team's cohesion and focus.