First of all, replace/buy QUALITY tools. e.g park/pedros/etc. Just the basics that are used most- cone wrenches, pedal wrenches, cable cutters, 3rd hand tool, chain tools, etc. And buy lots of quality allen wrench sets- T handled set(s) and loose keys. A couple of metric box end wrench sets are always super useful. LOTS of patch kits- or see if you can buy a ****load of patches and glue in bulk. Lots of different freewheel removers are also super useful.