Veiled here! I've had five, and I stick with the "let them come to you" method. The thing about Chameleons is that they don't usually like people, so you have to take baby steps with them and early socialization is best.
Start by just spending time in the same room as him. If you have paperwork to do, grab a chair and a clipboard and sit by his enclosure while you do it. I all of my "babies" in my room, so they spend a lot of time with me no matter what.
Once he feels comfortable with you just being around him and near his enclosure, try hand feeding. I know, it's not for everyone, but do it for the sake of your cham. If you have crickets, grab them by the leg and offer then to him. Worms and other feeders you can hold in the palm of your hand. If he doesn't show interest at first and backs away from you, don't worry, just try again next time. This point of this is for him to see that you are a FOOD SOURCE, and this is key.
Later you can start to offer you arm or fingers. Never ever grab your chameleon and force him out (unless of course there is a medical emergency, then use common sense). Think about it: how would you feel if you were comfortable in your bed and all of a sudden some huge creature grabs and drags you out. Probably wouldn't like that too much, huh? If he wants to be handled, he will approach you. If not, then let him be. Remember that chameleons are more of pets to watch as opposed to handle.
The goal here is basically to avoid unnecessary stress and prevent injury. Just take it slow and have good patience.