When you go for a ride, especially for a long one, it’s super important to have with you a multi tool in case you need to adjust your brakes, repair flats etc. Everybody knows that.
In my experience the situations that requires some basic tools are so common I would dare to say it’s rare to go for a big ride or a tour and come back without having used some Allen keys. Most cyclists have a small multi tool in their saddle bag that can solve the basic issues with the bike. I would recommend to buy one, but I have a cheaper solution that works beautifully and looks very nice. And maybe its more convinient as well as it can pack things that a multitool can’t, like patches and cable ties. Collect your spare Allen keys (if you have some IKEA furniture, look in your tool drawer, you most certainly have some), maybe a short screwdriver, patches, few cable ties and pack them into a nice little bag that you can always have in your saddle bag or even in your fanny pack. I will show you how to make a super neat one with just a trashed inner tube.
You can use this very functional design to make wallets, coin bags, pen bags etc