Hi - beginner question here.
I am trying to improve my current setup. I am connecting a servo motor to the Arduino. Currently it's connected via a male + soldered extra long wire. It's a bit messy and gets tangled with other wires.
I'm thinking of just buying a long male to male jumper cable and place the Arduino closer to the servo. What is the longest male to male jumper single cable that I can find? Is this a good idea (reliability?). Thanks!
It is a good idea to have the wires as short as possible. It is an even better idea to learn to solder so you make your own leads.
You can make your own however, the initial layout of money can be a bit high.
See Pololu connectors.
example pre-made 12":
If you mean "a servo" as in a RC control model servo, then there are plenty of extension cables available on eBay and similar.
Equally important to keeping cables short, is using cable as such - with the wires bundled together either as ribbon or in a jacket.