Pinner Tool Roll
If you are riding anywhere, you should always have a tool bag...even if it just contains few basic tools. I love having a tool roll to keep everything in one place. Also, I do not carry a ton of tools but just the basics that will get me out of most scrapes (we are not talking rebuilding an engine on the trail).
The Mosko Moto company make two tool rolls. The Pinner Tool Roll is the smaller of the two and the one I use. The roll itself is not waterproof but it does come with a waterproof cover.
I like have this additional tool cover. When you pull out the roll, you can use the cover on the ground to lay loose parts, nuts, etc and keep them from getting lost and also from getting dirty.
For my bike, I have attached the tool roll to the frame under the rear of the seat using Titan Utility Straps (love these things). If I leave any of my panniers at home (which I frequently do), I still have everything I need to fix a flat to tighten a screw, etc. Its tucked away so it does not interfere with my riding (sitting or standing). I do not ever carry a passenger so not sure it it would get in the way for them.
So what should you keep in your tool roll? I hate that question since it is really up to each individual. I have valve caps, cores, and coring tool for the tires (I also have a a tubeless repair kit AND sidewall repair kit that are NOT in the tool roll but actually under my seat - not shown). I have a set of box end wrenches and sockets for the most common bolts on the bike (you just need to go over them to see which you need). I have a 3" extension for the 1/4 socket wrench. I also carry a set of hex and torx bits that will also fit in my 1/4 socket. I do not carry any allen wrenches since I have found these to be difficult to use in many situations. The socket seems to be a better choice for me.
I also have electric tape, duct tape, wire, zip ties and a few other odds and ends. Lastly I keep JB Weld Water Weld and Loctite Glue Stick in the bag. That is really about it.
Now here is a tip that someone gave and EVERYONE should use. I do this now everytime I work or do anything on my bike. When you need to do any work on your bike (no matter how small), try to ONLY use what is in your tool bag. Not only will this give you actual experience using those tools it will let you know if it is the right tool OR if you are missing any important tools.