Allen key grips
This is an easy yet very useful idea. Adding your own grips to allen keys makes them more comfortable and also easier to use if you extend the handle.
Selection of FORMcards
Melt the cards individually in hot water
Mould the formcard around the handle of the allen key
Make sure the formcard bonds to itself all around the handle.
You can roll on a flat surface to give a neater finish or push your hand into them for a custom grip
Leave to harden
Once hard the handles should be removable so that you can still use both ends of the allen keys