My pup had a good chase instinct but he had no idea that he was meant to bring things back, this was being reinforced by daughter throwing the ball and then chasing the dog around the yard to try and get it back.
The first thing I had to do was get my daughter to stop chasing him, which took almost a week.
Then I got 2 balls, I'd throw one and when he chased it and picked it up I'd call him,at first he would not come back at all so I'd just throw the other ball and when he picked that one up i'd call him and I just kept repeating until he fluked it and came back, when he did I made a big fuss, praised him and threw the other ball.
After about 2 days he was coming back about 50 % of the time so I started saying give and putting my hand around the ball and just repeated saying give until he let go and then I praised him and threw the ball again, I tried not to make it a tug of war and just waited until his grip loosened before taking the ball. if he didn't give the ball to me in a reasonable time I threw the other ball.
In less than a week I had him willingly retrieving and releasing 1 ball over 90% of the time.
In 2 weeks he is almost 100% reliable, but I only do short training games and keep a good eye on him in case his attention starts to wane, if it does I stop the game before he gets distracted.
I didn't want to use food rewards for the game as the ball seems to be enough motivation and I thought the food might be a distraction.
The 2 balls method works great, I've had cattle dogs that have taken over a month to get to that stage when trained with 1 ball.