In every group project, notice who did the work and who just did the talking at the presentation.

Visibility and contribution come apart very easily in groups. Four confident minutes at the presentation can make someone look like the engine of a project they barely touched, while whoever did the work at midnight says nothing. Nobody has to be a villain for this to happen, because rooms reward whoever is standing in front of them.

Keep your own record of who did what. Name contributions out loud when you present, since one sentence redistributes a surprising amount of credit. Then notice who does that for you when the roles reverse.