This is a new one on me as I didn't know that tobacco grew from leaf propagation. Tobacco does grow like crazy once it gets going, about 3 months from seedling to 7 ft plant even in my temperate climate in Summer. Just let the plants grow as shown in my hub, don't fuss over them as they're hardy, just make sure that they have at least a 2 ft spacing from each other or other plants, they'll transplant OK at this size if you have to, but better if you don't as it checks their growth, not a great worry.
When the plant is mature, harvest the leaves as normal and check google on making cigars, - I haven't made them but I know that there are some good sites with common sense instructions around. I'd also suggest that you let the plants flower and save the seed, you'll get enough to plant half of Kansas and be very popular with your smoking friends!