It is a process.

- Think through all the things that could go wrong that you would be willing/able to fix on the road. Just get the bike out and go part by part. Tires = road morph, quick stick, tire patches... Just do the whole bike. There aren't that many things bikes are pretty simple.

- Then figure out what tools are required to do the stuff you would be willing to do on your specific bike, not mine. Go bolt by bolt. This is where the uber custom touring bike could be built to do everything with a handful of allen keys etc... while it might take two wrenches and a third hand tool just to tighten the brakes on someone elses bike.

- look at your likely tools and figure out ways of doing stuff that may be more dual purpose, for instance could you weld something to something and create a hypercracker that is also a pedal wrench? A simple example is one cone wrench and one small adj wrench, if it will handle more stuff on the bike, like one side of a brake adjust. But only if the adj wrench is light enough. Don't buy kits or multi-purpose tools half of which don't fit anything on your bike or aren't matched to the torque required for the actual bolt. An 8mm wrench with a 2 inch handle is not going to get you too far.

- anything you can't fix or won't carry the tools for because the cost benefit isn't there, either maintain now, or have serviced.

- Generally peruse places like this for the likely horrible problems like driveside spokes, and either gear up or build for the ages, or both...