Feed survivors only just enough to keep them alive due to the scarcity of food. Only feed them every other day. Save your extra food for times when it becomes scarce. Because survivors do not sleep overnight, when things are dangerous, put them on guard duty during that time and rest them during the day. The more people you have defending, the better. If possible, give them weapons to increase their stats. As day breaks, send tired survivors to sleep and send one of them to craft. Switch jobs as soon as one is up to always have rested survivors. The characters and items you are given affect your chance at survival. If you have characters with no vices, try the items used for vices to get some deals. Build your base at the bottom of the house and try to place as many survivors in one place as possible to reduce the distance that has to be covered by them during the day.