It's probably still the packing or heat management. Try to keep part of your pack consistent and change one thing about it then try something else, if that doesn't fix it, change something else while keeping a constant. Pack the same every time and use different holes one time. Then Pack the same and use bigger holes, try again with smaller holes. Pack again and start with less heat on the bowl (hang the coal(s) off the edge of the bowl) and with the holes you had the best results with before (a comfortable draw and good airflow is most important) slowly add more heat until you're getting a good amount of smoke but no cough. (make sure the coals are heated red throughout as well, no more black at all) Remember, too, the bowl has to warm up so give it 10 minutes or so before you add more heat (pushing the coals closer to the center of the bowl). What hookah, bowl, coals, and tobacco are you using? Also, pictures would help (of your setup, the coals on the bowl and started, the foil after poking holes, and the tobacco in the bowl before you add the foil)