We have made a dozen no-budget feature films and several shorts. We have found that when we announce the audition, we give the actors as much info about the shoot as possible so that there are no surprises...such as the length of the shoot, how many days, which days of the week, pay/no-pay, shooting in the woods, etc. All of this info will weed out most of the problems ahead of time.
One problem that we have had on each and every production is getting enough qualified actors to fill all of the roles...often the actor who "looks" best is the worst actor, and the one who doesn't "look" the part is the best actor. So we solved the problem with giving all of our actors exactly the same pages for the audition...we could compare apples to apples so to speak. The best actors got the best roles, regardless of their look. (The women, of course, had a different "female" script). We rarely gave them more than 3 pages to memorize.
In the end, around half would not show up for the audition. And of those who did, we lost more because there work/school schedules did NOT match our shoot days. In the end, we always had just "barely enough" actors for all of the roles.
Also, even though all of our films were "no-budget", we always PAID our actors $25/day to
"cover their gas", and we always fed them. This token payment of appreciation REALLY makes
a difference in their attitude and work ethic...it makes the project "look" and "feel" like a PAID gig even though it's only $25. You will discover (as we did) that you get what you pay for.
We also tried to keep our shoot days very short...generally less than 6-hours. Actors like this because it's less dialogue to memorize for the day.