There are several reasons your fire may put out a lot of smoke. But one of the most common issues is the wood used. Excessive smoke is a frequent sign of wood not fully combusting as it burns. This can be caused by burning wet logs or incompletely dried firewood, as well as the presence of unpleasant mold or fungi.
Any yard debris like leaves or needles mixed in will also produce more smoke. Finally, certain types of wood are smokier than others in all cases, including most softwoods like pine.