Due to lack of space, bring items on board with forethought. If the item you bring on board has at least two uses, it is even better. For example, this rubber strap wrench has multiple uses:

1. opening jar lids
2. remove oil/fuel filters
3. open raw water filters, lids
4. drinking water filter removal
5. twist pipes, other

This handy-dandy rubber strap fits around objects of any shape to loosen, tighten or hold without surface damage.  Two sizes cover most situations.