My late father grew his own nicotiana plants, threaded the leaves on wire and hung them in the greenhouse to dry out. As they turned brown they looked similar to kippers being smoked.
He bought some tragacanth gum and perfected the art of rolling decent coronas, albeit a little wet. To dry them out he put them on a baking tray in a low even with the door slightly ajar. Magic. They turned out like bent bananas and you had to light them near your ear.
In time the cigars straightened out but they were buggers to keep alight without suffering from collapsed lungs. We ended up passing a knitting needle through them to help them draw.
His pal, who worked for a chemical drug manufacturer, suggested he add a little saltpeter in the rolling process...
He did, we both smoked them.
Don't ever say ttfn hasn't got the spherical objects ;)