When you’re wiring a circuit on a breadboard, neatness counts. If you use color-coded jumper wires that fit precisely, you can see your circuit clearly and track down errors easily.
There are two types of pre-cut jumper wires: the long, flexible ones with little plugs at each end, and the solid ones that are cut in 1/10″ increments to match the breadboard spacing. The flexible ones make it easy to build a circuit, but you end up with a rat’s nest in which errors are very hard to find.
On the other hand, the solid ones are color coded by length, which I find unhelpful. For instance, I want all my positive connections to be red regardless of how long they are.
Cutting my own jumpers seemed a hassle. It isn’t easy to trim 1/4″ of insulation from each end of a teeny wire, and get the length exactly right. What to do? Instead of cutting the wire first and then trimming the insulation, I trim the insulation and then cut the wire.