It is hard to be a boss when you aren't there. My lab turned into the wild, wild west after two months, culminating in a glorious accident in which no one was injured.
I have a group of <10 people working on two themes. Prior to going on leave, I separated my group into sub-groups based on theme. A post-doc led each sub-group with weekly meetings and presentations. The post-doc wrote me weekly reports on the activities of each member of the sub-group. This worked very well to keep people going.
The big challenge was that no one was playing the role of enforcer. These post-docs wanted to be everybody's friend, not everybody's boss. After two months of leave, my lab became dirty and unsafe. I didn't go into my lab often enough to notice. We had an accident that required us to call EHS - an accident where someone could have been critically injured. That accident was a huge wakeup call that maternity leave was over because my lab needed me.
In the wake of the accident, I have now schedule weekly lab cleanups centered around group meeting. I use this cleanup time to scrutinize every bottle and surface. Our group meetings have a safety presentation now. I made every member of my group complete safety training, regardless whether of they were out of date or not. We had a special lecture on safety from our College's rep. I interviewed every lab member and asked them about what safety violations they saw and what was troubling them. I did not ask them to name names, just name the actions. What came out of it was pretty much everyone's desire to be safe and be clean, but no one wanting to do the work, hence the weekly cleanups. One of my lab members actually told me that they wanted me to law down the law, and that they missed me.