Stick to the fundamentals. Volume, Rate of Speech, Tonality, Melody and Pauses. Record a 5 Minute Video of yourself, and look at it 3 times. 1. Only listen to the audio. Second time, only look at the visual with sound. 3. Get the transcript of your words and look which words you are using, and how often you use filler words or non words( uhmm, ähs, you know, etc)