When trying to craft gears, wait 10 minutes between crafting the first to the second. Gears that require another gear as an ingredient should be given a longer period of time (15-20 minutes) between crafts. So far, I've gotten quite a lot less fails than normally using this technique.
Don't constantly send sprites out to do jobs. Give them a good 5 minute break between to give them some time to regenerate some energy or something.