Have a friend ruthlessly evaluate your energy. You may not be aware of how you’re coming across.
Think about the great storytellers, commedians, politicians, actors who have an amazing stage presence. Study and emulate their body language, style of talking. So much is about volume, timing and delivery!
The Attitude of Gratitude is about being respectful and appreciative. You don’t bad mouth former employers or begrudge your current situation. You gracefully acknowledge the learnings they’ve afforded you. You acknowledge the value of your interviewer’s time by being puntual, staying on topic and sending a thank you email SAME DAY.