Use silica gel to keep tools from rusting. Packets of silica gel you can find in shoe or pills packs. They absorb moisture from items and can be reused. Just put a packet of silica gel in your toolbox and rust will have no chance!
A piece of charcoal or white school chalk absorb a lot of moisture. One piece of coal or chalk is enough to prevent rust in a small tool box. Wrap the piece of coal in a nylon sock and put them into the box to keep your tools and toolbox rust-free.
To prevent rust in toolbox wipe the tools with microfiber cloths after each use before storing. Microfiber cloths have a very good cleaning efficiency and clean residue free. Oil the tools regularly.