For my project, I went to that staple of American shopping experiences: Walmart. There in the Halloween section is the 97 cent box. I found an assortment of small sippy cups crying to be liberated from their straws and modded to be small, scary light sensitive balls of evil. You may chose to place the eyes into any item or even a board to hide in a window or the bushes.
I placed the photocell and LEDs on the ends of male to female jumper wires. Any hookup wire will do, but the jumper wires hook right in to my breadboard and the components. You will want to trim the component leads a bit before placing in the female end to avoid the wires touching and shorting out.
Put the batteries in the holder and for Trinket plug into the breadboard with the red lead to the BAT+, the black to GND. If you use Gemma, plug the battery holder JST (white) connector into the Gemma battery socket. Lower the board into your selected container and thread the LEDs into the eye holes. If you want, a dab of glue will hold the LEDs in place. Thread the photocell through a hole in the top and secure with tape, Sugru, or other substance being careful not to twist the wires or make them touch.
Turn on the curcuit and put the lid on. Now when it is dark enough, the lights will fade in and out and "blink" (go on and off quickly). Enjoy your scary eyes project.