lol. For me it was always dependent less on how much planning I WANTED to do and more "when are the actors all available at the same time," so between two and four months of preproduction. Scripts were always written way in advance.
And success is weird, but when I saw a finished product of the thing I'd worked so hard on and got my first fan who wasn't related to me, that felt like success. I'm sure my threshold will increase as I produce more, but that was pretty darn cool. Someone made a GIF of me, too, which was radical.