Don't ever give out "free" treats. Make your dog earn a treat or praise, even if it's just by you asking for a simple "sit." A dog needs to understand that in the pack, the pack leader (YOU) will provide food to him. But it's not free. He has to work for it. If you begin giving your dog treats without asking for something in return, the message to him might be understood that HE is the pack leader because you are serving him, and it could undermine training. And when I feed my dogs, they must sit calmly, and wait until I let them know it's OK to eat. I am the pack leader. I hunted the food for them (as far as they know) and I will give them permission to eat the catch. The same goes for even small treats.
Never pass up an opportunity to reinforce the fact that you are the pack leader. And also, never miss an opportunity to teach your dog that if he listens and does what you ask of him, he will be rewarded. These are both important in training a well-behaved and happily lead dog.