Rehearsal

The part people skip.

How to do it

Out loud, standing, at full volume, timed, at least three times. Speaking in your head takes half as long and teaches almost nothing.

Rehearse the opening and closing until they are automatic.
Record once and watch it, however uncomfortable that is.

Notes

Bullet prompts rather than a script. Memorised text collapses under interruption and sounds recited; prompts let you speak naturally while staying on track.