This is my simple jig that I use with my ISP programmer to reflash the Trinket bootloader. I thought it may be helpful for others.
When the Trinket is viewed inverted, the connections follow a standard tiny85 DIP with physical pins #1 and #8 most distant from USB connector. See pix (right-click and select open in new tab.)
Cut the foam wide enough to create significant expansion in the width of the pins when inserted into the protoboard. Then squeeze to slide the Trinket onto the pins. Move vertically a few times to ensure a good electrical connections. Now use jumper wires to your AVR-ISP programmer or ArduinoISP.
High Resolution Images:Parts:Side view:Top view showing ISP connections: