You know what would really prettify and simplify my arduino projects? If I could easily buy wires with plugs already on them that fit breadboard-pitch pin headers. The Adafruit FTDI cable has a 6-pin plug on the end that fits right on the header of the Arduino. I wish I could just get pre-wired plugs like that. RC servo lead wires fit the pin headers, but RC shops want like $5 each for RC servo extension wires. Why is this basic thing so hard to find at like Sparkfun or something?
I make my own. I use male or female header strips, cut to the number of pins required and strip colored ribbon cable to the number of conductors required. Takes me two 3rd hand soldering aids to careful solder up the connectors, but with a little practice I've been pleased with the results. Solder the wires to the short end of the male headers.
A little hot glue or epoxy can insulate the exposed solder connections if you wish. Important that the wire ends are equal distance to the pins so that force when unplugging is spread equal to all wires. So not as high a quality or as good looking as factory made header cables but at least available when needed and cheap to make. 
Lefty
Another option is terminated wires that plug into crimp header connectors, from pololu.com.
Here are some plugged into female headers in a box I am building.
That's what I'm talking about. I'll have to check out that website. In the meantime, I bought a bunch of female headers and I can at least solder wires to the pins on those and use them for plugs. My point, though, is that nice, already-made plugs would really be nice for quick projects.
The pololu parts are nice for that. Come on single row, dual row, 1-2-3-4-5-6-7-8-9-10-12-16 pin versions.
I used 6-pin length for the promini and arranged the power/ground & I/O pins to suit my needs.
On the other ends, I used 2 5-pin lenghts on one side and a 2-pin & a 3-pin on the other.
I bought several bags of the different size crimp housing, and with 1-2-3-4-5-6 x 1 length housings have had a lot of flexibility. I have used male-male terminated wires in the picture here, and in other cases have used female-female to slide onto 0.025" square posts as header pins.
I made a mistake with hole size on the 2 cards on the sides, the female headers had pins that fit nicely; the original plan was to have square posts, but they wouldn't go in the holes.
The promini will take square pins, not sure why I used female headers there. I think I had some available from a shield prototype kit, and stuck with them. Or maybe it was difficult to locate single row male header pins that seemed suitable.