I think it's interesting that you never noticed they smoked .....
Smoking in uniform and out the front is a no no.
I smoke ... and I smoke outside the salon, I am booked 8 hours a day, and 8 clients in that time, sometimes more (fixing the odd nail in between clients).
I don't have time for break as such ....... my clients understand I smoke and will often say "do you want to have a cigarette before starting me"? They know how busy I am ... we have an understanding and that's just the way it works for me.
I work alone and don't have much choice.
Something you have to be careful of if you start setting rules for them .......
they may start setting rules for you .....
IE,: strict starting times, strict finishing times, strict lunch breaks ..... all the things that employees are entitled to (and can bring you undone by not playing by the rules).
I think some fair flexibility is a great approach and some simple ground rules. ........, this can keep everyone happy
I appreciate a non-smokers right to not breath my smoke (fair enough) for health more than anything else.
I wish people with strong perfume appreciated my sense of smell too (sometimes so strong I can taste it).
I wish for lots of things (along a 2 way street), but find myself having to be "tolerant".