My board design files are up on Google Drive.

ATTiny85 Jig

This one was pretty straightforward. Having the components in place ahead of time made things easier, although also I had less freedom - since it's meant to fit as an Arduino shield, I couldn't move the two rows of through-holes.

ATTiny 85 LED

Also very straightforward, once I realized that apart from the ground and power rails, the two components - potentiometer and LED+resistor - were each connected to only one side of the ATTiny.

ATTiny85 Transistor

This one was a little more work, but more fun. The schematic helped so much here - in particular in identifying which components essentially acted as a group (namely, the LEDs with their individual transistors. I could have made the board narrower, but I assumed the large capacitor would stick out of the board, so I left a space to the right of it for the potentiometer to sit, with its knob pointing to the left, such that neither the large capacitor nor the ATTiny would block the knob. I was sure I was going to have to go through the board and run a wire on the other side between the transistor and ground, until I realized that by rotating the two power connectors, I could have a nice arrangement with the ground rail on the outside and the power rail on the inside.