It is especially important to give reassurance to a new bird. A calm bird is not as noisy or frustrated as one in a tizzy all the time.

(1) Give the bird a coolish shower, we don't think they like warm water.
(2) A warm meal calms a bird and then they usually want a nap.
(3) Taking them outside in their harness and leash or in a secure carrier is considered calming to a bird as some of their energy gets spent on the trip and is probably more stimulating than reassuring, but if they enjoy this then your reward is a happy bird.
(4) Exercising a bird until it is out of breath is another way to making a bird feel good physically and emotionally.
(5) Sing soft songs to them for calming them and to reassure them of your love. Choose a special song, all their own, and sing it everyday often to them.
(6) Speak softly and gently to them. The only firm words I try to use to my birds are NO BITE.
(7) Share a meal with your bird! Let them eat from your plate or while
sitting on your lap. Birds love to eat with others in the wild, and you
are their flock in their home. They are social, so eat with them.
(8) Laying down with their favorite person is so reassuring for a bird.
So is watching you sleep. If you take a nap sometimes, take it near the
bird's cage as it is reassuring to the bird to be with you in restful
moments. And when you wake up, your greeting is awesome.
(9) Sit when you hold them, don't stand. They know you are not going to hold them long if you are standing so sitting is more calming and loving.
(10) Calm yourself before you go around the bird. Think cheerful, lovely thoughts and take a deep breath before you approach the bird.