Having only worked on the one feature - many moons ago! I can only speak of that experience - although it was for 4 1/2 months from casting to pick up's.
And basically everything that could go wrong did - lol! However I believe you learn more from such than success.
Anyhow, the one thing that did go right was we managed to get over a dozen 'main actors' to commit - first through 3 weeks of rehearsal but then 3 weeks of shooting (+countless p/up's).
Unfortunately, my mate was the lead/director/producer etc... so you can all probably guess how it ended up BUT I probably got the lesson of ten movies because of "how NOT to do things!"
In the end we probably had about 35 speaking roles and as I say an enormous amount came along for the ride for a couple of months!
Oh yeah, not one cent was paid! Sure they got pizza and a few bits and pieces BUT no one was paid.
And I put it down to casting the 'right' person for the role and having adequete rehearsal time to flush out the flakes and prima-donna's etc. Of which there were some...
Plus of course contracts for a $1 and copy - that was all.
It was quite an experience and as I say I learned sooooo much - probably why it's taken all this time to want to produce one myself - lol!
Jim