I use a Char Griller with smoker box and while the food is very tasty, I know I could do better. I have noticed when I dump the metal box containing the wood chips that much of the wood chips did not "burn".So, I use a metal box with dry wood chips set in the inbound air path (right side of coals) as the chimney is on the left so I want the smoke to go up into the meat not just out the chimney. This is a charcoal grill. Below is a picture of the indirect cook I did today. I use the same metal box when cooking direct as to set the box on the coals to me (maybe this is my mistake would be blocking the heat from getting to the meat.The metal box is somewhat visible with the un-burned wood chips on the right edge of the picture.