A presentation outfit you can move in
Choose an outfit for the room and what you will do in it: speak standing up, reach for controls, walk to a seat or use a clip-on microphone. The aim is to remove small distractions while you present. Your audience and venue set the level of formality.
Start with structure you can wear comfortably
A blazer over a simple top with trousers or a skirt is a workable starting point when the setting calls for it. Wear the jacket open if it hangs well that way and the dress code allows. Pick a quiet shoe you can stand in, rather than testing a new heel on the day. If the event is less formal, a neat knit or shirt can carry the same sense of preparation.
Check what the room changes
For a filmed talk, test the outfit with the actual camera if possible. Fine patterns, glossy accessories and dangling items can distract depending on lighting and sound. If you will use a microphone, wear a neckline or lapel that can hold a clip and ask the organizer where the transmitter goes. A pocket helps only if the cable reaches and you can move.
Do a one-minute rehearsal dressed
Stand, raise an arm and sit back down. Check whether the jacket rides up or the trousers pull. Record a short test and listen for jewelry or fabric rubbing if sound matters. Choose the version that lets you focus on speaking.