I recently attended a meetup about another topic in which the organizers were trying to stablish a new group.
The intention was to show cool toys and then show a work flow to obtain results. They had 4 working prototypes of the gadgets, one area with 2 big screens, a chill out area (with drinks and sandwiches) and 4 people that could have provided a guided tour through the topic of interest (we were supposed to leave with a present built there and then, which would have been a nice touch).
First of all they could not control who was assisting.
Then they just said "oh well, just follow one of us and we will make four groups" without making sure all the groups were about the same size.
They didn't have a plan of action, which meant people began to wander from one group to the next until they felt comfortable, this meant one guy, perceived as more informed, had way too many people (and because he was better looking, all the women stayed with him) while another guy, far more knowledgeable but a bit shy, ended standing almost on his own.
One of the guys supposed to organize things was hysterical because he knew it was all a mess and made everybody else moody.
They haven't tested that they could use the screens for a presentation,they didn't work which mean they resorted to sit with their laptops (Apple ones of course) on their knees "showing" others how things are done (how many people can stand close by and see anything at all?)
You see, some basic planning (dividing groups, assigning them leaders, sketching a plan for the meeting, testing equipment) would have made a success of the meeting.
As it is I am pretty sure they will be lucky to have half of the people back (several of them were actually investors interested in the technology, talk about wasted opportunities, I saw several of those people shaking their heads in disbelief).
We techies forget about these things, but they are important, this fashion of "unconferences" and doing things in the spur of the moment are great in paper, but frankly only scream "our group is lazy and disorganized", if you are organizing a LUG, do it properly, it will take lots of time and effort, but if you can't put this then you shouldn't bother at all, but if you do it properly you will make friends for life and connections for the future who will remember you as the organized guy that kept things going.