Recently I ordered 50x PCB assemblies from Elecrow that i want to sell on tindie,  but I need a testrig for it. I quickly made one with prototype board, 0.1" headers, a battery, a capacitor, some leds and resistors.

I just press the board-under-test between the two rows of angled male headers, and then the solar input gets 1.5V from the battery and the LEDs indicate the 3.3 and 1.8V outputs work. Basic functionality checked!