As your dog gets better at the ‘Take’ game, and he begins to predict that you will give him food and he spits the object out to eat the food, you can begin to name that behavior to. Say “Give” as he opens his mouth to get the food. Continue to practice this for a while.
As he gets better at taking and giving, begin to slow down your reputations. Ask him to ‘Hold’ between ‘Take’ and ‘Give’. Pet him, and praise him for holding that stick. As he gets better at this begin to let go of the object briefly as he ‘holds’ it. Continue to praise and reward him for getting it right. If he drops the object before you ask him to ‘Give’, pick it up and ask him to ‘Take’ it again, or encourage him to pick it up himself.
Once he has a good understanding of these three things, it’s time to take it out to playing fetch. As he comes back to you with his fetch toy, tell him to ‘Hold’ then reach out to him, grip the object and say ‘Give’ be ready with lots of rewards and treats when he lets go. Don’t try to play tug with him while doing this, or encourage him to tug with you. If he tries to start a tug game just let your hand slide away and walk away a foot or two, and then try again.
You can use food as both a distractor and a reward in this. Hold the food out just above his nose, and encourage him to hold. This will teach him to hold his head up so you have easier access to the object he is carrying. Then once your hand is on the object you can ask him to ‘Give’ and reward him with the food in your hand.