Screen Credits are important to get right. Leave people out, spell their names wrong - there are all kinds of ways to annoy your fellow film-makers.
Most important of all - be sure to credit for all the key roles on your film. In general, credit for the key heads of department will go to one person only. For short films, there should be only be one producer and one director. Usually (but not always) one writer.
If you need to credit someone else, give them a title such Associate Producer or Assistant Director. Extra writers can be credited under "Additional Story".
Make sure you credit (at least) the following roles; Director, Producer, Writer, Editor, Art Director, VFX Supervisor, Animation Director (or Head of Animation), CG Supervisor.