If an event organizer is driven to support a cause, he/she shall look into every means to provide the best before, during and after ...period!
After doin so if there were to be any feedback it should taken positively and pls learn to deal with empty critisism...patiently!
If its a club wanting to boost sale by in cooperating a platform for local muso's (well being a win-win situation) please do so with a transparent agenda and seek the advice of already available promoters and by having a third party in action and this will keep away mishaps/misunderstandings.
An event needs proper promo done way in-advance, avoiding clashes with orther gigs or similar events. Do proper planning, not poking on chance as it will flip and die ....
Seek bands that are wanting to give a good show and look into their past activities as a band, learn a little about their history...this will keep away surprises...the unwanted ones !!
Ask feedback from bands and audience alike and be true to your concept.
Finally have a good repo with the local law (events licencing & civil defense) by giving correct info before a gig ...this will be a blessing (trust me on this one).
Please do not expect musicians to lug their own 'heavy gear' for a gig, try cutting a deal with gear rental company or at least get used gear which a club should own if its into live music. This shall be the standard anywhere in the world ...if not its a RIP OFF !! You rather get a ghetto blaster and promote line dance
Keep a good tech around to help with glitches,...and for a small club, sound is not a big deal as a small mixer will do the trick. Make this into a platform as well for student's doin sound and pay them a token !
Set an age limit (according to local law) if you want to sell alcohol. If the underaged kids are your target then avoid alcohol altogether or set time slots and look for alternative ways of keeping the adult crowd in house after the gig.
Get able bodied men who are known in/part of the local scene to help with crowd control ... many will do so for a couple of free entries with drinks.
Finally ...Be a freind of the scene !!
My advice is derived from my own experience of doin gigs here and various places around the globe !