Larry blogged about his DIY AVR ATTiny85 programmer and development board:
Starting from upper left is the 6-pin AVR programming header. I chose it because it has +5 and GND as well as the programming signals and can power the board. Next a red LED to show power to the board. Upper right is an LED tied to pin 4 for the default blink ‘hello world’ program. But with so few pins available, a jumper to disconnect the LED for pin 4 in case the application wants that pin. Below it is a reset switch.
Next across the bottom are headers, arduino like, bringing out each pin as well as an extra +5 and GND. There never seem to be enough. I also thought it could support a mini shield too.
Project info at Larry’s KB7KMO blog.
A small label at the top would be ideal. If you have a box full of this kind of protoboard thingies, then labels help, believe me…