I designed this snowflake from a real snowflake photo to fit (6) 5mm led's. I used the flickering yellow ones from some old battery powered candles. I printed the small one but made a larger one too for people that have larger printers.

https://www.youtube.com/watch?v=qKpH26xlNyU

Use natural/clear PLA and concentric top and bottom fill. Print two snowflakes and superglue led's into one of them being careful to keep the leads of all the same polarity. Bend the leads so they touch each other and solder the LED's in parallel. Solder the battery wires to their respective sides of the circuit. add superglue to the tops of the LED's and sandwich the other snowflake on top. Add batteries and place on tree!