I think this is the best I can do....
Day 26's question is "Favorite Mundane Item".
My favorite mundane item is one I haven't seen in any player's handbook or equipment list...and it isn't on my PC sheet (yet...there is a good reason). That item is a good old-fashioned toggle rope. This great piece of kit is pretty old, having been used by sailors since....well, forever. You may have heard it by a more recent name, the Commando Rope, so named because a lot of WWII Commandos carried these.
It isn't that uncommon for PCs to have maybe 50' of rope somewhere in the party, but even with nice silk ropes that adds up to a lot of weight and bulk. In games where encumbrance isn't an issue....well you tend to find a LOT of rope spread out within the party. Maybe it is already knotted for ease of use when climbing.
If you GM is a stickler for encumbrance, like I am, replace that bulky rope with smaller sections of rope spread throughout the group. Want to keep your GM from making you roll for your Rope Use skill? No problem, make sure these small sections are all toggle ropes. Make them 10' between the toggle and spliced loop and you'll be set.
I would just pay extra for quality rope and an have and expert do the splicing. I'll probably write something up for this wonderful item.