I started with the basics but over the years my flight box has gotten a lot bigger, this one is on wheels!! I carry a lot of spare parts, most of it little things like screws and little things that come loose or break. I carry a pretty good assortment of props for different sizes of engines. We tend to borrow and lend out at my field to help keep guys in the air without going home. CA glue is always nice to have. I go to the dollar store and buy the three pack so I don't need to have a tube of the stuff, use it once and toss it. Fuel line is another top item.