Handling

Always Be Hands On
Bearded Dragons love attention, they are a very social and curious reptile. Handling your dragon is a big topic, and I always say the more the better. New dragon parents can be understandably timid about handling their pet. Believe me when I tell you that your dragon will not want to be held unless you hold it. Baby dragons can be scared when you try to pick them up, mouth opening, biting, jumping and flattening out their belly are all defensive moves. Dragons do this when they feel threatened, but can you blame them? Put yourself in their scales, they are tiny and practically defenseless, pretending to big tough is the only option. Your hand flying overhead grabbing at them is exactly like a predator swooping in to eat them. Also until they know you, holding them with a closed fist for extended periods of time will scare them, they will struggle to get free of the pressure.
Your Moves Matter
When you notice the above signs of defense don't feel disheartened, your dragon still can grow to love you. You need to train yourself on how to interact correctly with your dragon. When you are going to spend time with your dragon make sure you have a cleared out area on the floor, just in case they get away. Remove any items they can hide in/under. Then instead of coming at them overhead like a bird, lay your hand flat in front of the dragon, slide your hand to its face going under its chin. Let the dragon walk onto your hand like it was his/her idea. Like in the video below.
Unfriendly Adults
Now handling adults that do not like being held is a lot more difficult. In a perfect world an adult dragon you buy would already be calm and friendly, that is not always the case. Often times breeders are too busy to handle their dragons so you will have a bit more work to do. Hold them daily for at least 15min to help them get used to you. Use gloves when handling if needed and pick them up the same way you pick up the scared babies. Try petting them at the back of their heads slowly, out of biting range. And continue this daily until they calm down.
Dragon Love
 I don't think I would have fallen for Bearded Dragons like I did if they didn't love to snuggles as much as they do. Keep at it with giving them attention, it's a slow process, especially for adults, but it is worth it. Once they bond with you they will be calmer and more friendly to all hands. And eventually you will see them at their cage door, waiting to see you.