The very popular 595 shift register chip of the 74 series is used a lot by hobbyis because of its wide availability, good speed and simplicity. Just plug it on an arduino like shown in the tutorials and youi have 8 more outputs, put two and you have 16 more outputs ! (up to a lot of them actually, with only three pins !)
This is a splittable 40 pin jumper wire, it is super flexible, can be transformed from 1-40 pin jumper wire. With some of these, you will no need to worry about the jumper wires you got before do not fit your project, just split it and go.