Once the enclosure is prepared:
- Situate the Arduino
- Install any of your interface components, like pots or LEDs
- Install your input and output jacks
Remember that the LEDs need resistors between them and the pins on the Arduino. I used 150 Ohm resistors.
We'll be modifying the analog reference value, so if you want to use any pots you have to connect them to the AREF pin instead of the usual 5V pin.
For the 1/8" connectors (or anything that isn't on the same panel of the enclosure as the Arduino) be sure to use flexible wires. Otherwise it will be hard to close the case and the joints might break or other connections might come loose.