I direct a lot of shows in black box and store-front theater's and have had quite a few shows with cigarettes needing to be smoked. Because of the realism of the scripts and the close proximity the actors are to the audience, using fake cigarettes is not an option.
There are many companies that make herbal non tobacco cigarettes like Ecstacy and Honey-Rose. They are made with different blends of herbs. For example Honey-Rose uses a blend of honey, Rosemary, and marshmallow. Ecstacy has ones that try and resemble the taste of actual cigarettes if they actor is a smoker and prefers that. I always let the actor pick what flavor they prefer.
When I directed Annie Baker's The Aliens, The actor playing Jasper was a smoker and smoked reds so we got him Ecstacy Reds. The actor playing Evan was a non smoker and an 18 year old high school senior, and he preferred Honey-Rose and didn't fully inhale.
The smell (and taste from what I've been told) is not pleasant but smells more like burning paper to myself. The main difference (well aside from no tobacco or nicotine) is the smoke doesn't linger as long and the smell doesn't stick to the space, fabrics, costumes, etc. . Actually, the actor playing Jasper started sneaking in his real cigarettes one performance thinking I wouldn't notice, but I did and flipped out. His excuse was that the audience was complaining about the herbal cigarettes and "everyone prefers the smell of the real ones".... Right.
Honey-Rose actually makes fake marijuana that looks and smells (kind of) like real marijuana which is great for plays that have weed smoking in black box spaces!