How to train my scared bird to comfortably step up on my hand?

Be patient with him and always move slowly. Try having a treat you know he likes close at hand and ask him to step up by putting your finger under his chest in front of his feet like a ladder rung and push back gently. This will encourage him to step onto your hand rather than have to step back. Use the treat to reward him or, if he's still very flighty, distract him with it when you offer your hand to step up. If he likes being petted, use that as a reward for him too, always moving slowly to avoid startling him. Make sure his cage is located in a quiet, draft-free area so he feels secure and hopefully less nervous.

The best way to work with birds is to move slow and also reward with treats. Typically I pick a treat that Meenakshi will love and only have you give it to him. I would start putting it in his cage and slowly move to hand feeding. Than you can place the treat up your arm and as he becomes more comfortable he will stand on your hand. I hope that helps

It sounds like Cheeko still is wary of you, and honestly, you need more time to bond before focusing on tricks, especially if he is still flying away from you. Going back to a previous step such as hand-feeding, just being near his cage and spending time with him, petting him without handling, etc are all good previous steps to work on. You can then begin step-up training with a dowel or other object instead of your hand, that may help him train without being frightened by your hand or being handled. Training birds takes time and patience, so just keep trying, and if he seems fearful, give him a break, go to the previous step that worked, and then move forward from there.

It may take time and patience. You can begin by simply sitting next to the cage for short periods of time initially and increasing it as they acclimate. They will flutter about and move to the far side of the cage at first. Eventually, they will settle down and accept your presence. Move slowly and speak softly around the cage. Once they have completely acclimated, you can progress to placing your hand in the cage. Make no attempt to touch or hold them. Again, they will flutter, panic and move to the far side of the cage. Leave your hand inside the cage for ever increasing periods of time. Use small treats as rewards after each session. Eventually, they will become curious and may hop onto your hand if you have treats. You can teach the 'step up' command by extending a finger and gently pressing it against the chest while saying "Perch" or "Step up". From this point, you can work with them to teach additional tricks or whistles.

Keep at it! Some birds may always be slightly scared, or take a lot more time to get used to it. In some cases, it may be that this is the most your bird enjoys. Some birds may also be fearful while in the cage, but more open to handling outside of it, so if Pebbles has a playstand or something he enjoys outside of his cage you can work with handling there as well.

The best way to encourage this is to break the trick down into smaller steps. First, get the budgies used to you by offering a treat every time you visit them. Then, get them to eat from your hand every time. Next, start petting them every time you offer a treat. Then, you can start putting your finger to their chest right above their legs while giving a treat- most birds will naturally step up from this behavior. You can then start tying a command such as "step up" every time you do this and give them a treat. Any time they seem stressed, frustrated, or scared, returning to the previous step that worked, and trying again from there is best. You may also want to take a break for a bit to let them both calm down and relax before trying again. Also, finding a favorite treat and only offering it during training can help them associate you with good, fun things!

Time and patience are key to helping your parakeets get used to you, and each individual bird may bond differently to you due to their individual personalities. If your birds have a favorite treat, you can also use that by giving it to them every time you visit their cage or interact. I'm also including an in-depth article on teaching your bird to step up which can help with the bonding process as well: https://www.petcoach.co/article/basic-bird-training-how-to-train-your-bird-to-step-up/