Personally I'd rather have a tenant sniffing coke than smoking marijuana, which can leave an odor and possibly the need to re-paint after they leave.If they have been good otherwise, I would pretend I never saw this.

What about smoking? 

First I want to say hi, I am fairly new to the forum but I have been reading alot of posts and discussions. There's a fairly big town 30 min from me and the real estate market is definitely a buyer's market, and there...

She told me when she took over anyone who was the slightest troublemaker did not get their lease renewed.Anyone that SMOKED did not get their lease renewed.

Check furnace filter, smoke and carbon monoxide detectors, and other mechanicals and do a quick walkthrough.

If a tenant was noisy or had friends taking up all the parking spaces, or they were smoking in the apt, etc., it would affect other tenants, and we didn't want to lose good tenants.If we ended up with a problem tenant, we could just give them 30 days notice to leave (60 days, if they're been there over a year in CA).  

No Smoking is a big one for me , but be sure to look at your state's law and  regulations as different states have different guidelines.

Maybe you did get rid of the smell, but the new tenants smoke, too LOL.

Make sure the smoke detectors meet requirements - some have to be replaced if a certain age, make sure the batteries are new.  

My friend was seeking feedback because she is afraid it might be mistaken as a threat or offend the landlord if she shares this knowledge with her and the handyman, while intended for their own protection.....and by the responders above calling her "evil" accusing her of "narking" and "causing trouble for the landlord" and "pulling a stunt like this"....holy smokes, man.....I can see why she'd fear such a misunderstanding.