Medium is the rule.
Walk at a medium pace. Walking too fast gives the impression that you are hurried, unorganized, late, not paying attention and not available to speak to people. Walking too slow looks like you are tired, lack energy, unsure of where you are going, and again not paying attention.
Talk at a medium speed. Speaking fast comes off as if you may be trying to trick people (i.e. a fast-talking salesperson) or trying to pull the wool over someone’s eyes. Speaking slowly sounds like you are unsure of what you are talking about, hesitant, and also gives way too much opportunity for someone to interrupt you or cut you off before your thought is complete. It may also sound unintelligent.
Finally, use medium volume for the current environment, which is to say don’t be the softest speaker in the group which looks weak and unsure, and don’t be the loudest which comes off as attention-seeking behaviour and may look like you are arrogant and over-confident. Medium is the key, with a nice rhythm of pauses and stressed key words.
Incorporate this simple but powerful tool today!