I have them open for about 10-12 hours or so, but I never keep count of the hours as I usually close after the employees bail on me and go home for the day. I did some reprimanding and gave some promotions but I am not sure how much that helped. I think the issue is with the customers who have no questions, because they just come to hang out at my lot and chat to one another. They show up as early as 6 in the morning out on the sidewalk checking their phones. And some bring food from a nearby lot and leave it out on the sidewalk on my lot. The craftables are really for other sims to enjoy as I don't like everyone skilling up in every skill just so that they could enjoy craftables in the game. There is no option to scent the flowers yet with this sim I am currently playing though she is level 3 I think.