Be Confident, Not Forceful
Being confident around you bird is very important to increasing trust and decreasing aggression and fear. The joke that “birds smell fear” is true to a degree. Birds can understand our body language and see when we are fearful.
But… there is always a but. Being confident and using force are difference things. I see a lot of people say “be confident” and then turn around and use force. I see this especially with the step up. The bird shows clear body language they’re uncomfortable (opening their beak, bowling their head, puffing up, lunging) and the “confidence” part would be pushing though and pushing your arm on the birds legs to make them step up.
Confidence is not flinching and shaking, which shows and unreliable perch. Force is ignoring your birds body language. You are still a confident handler reading and respecting your birds body language.