Using the floral tape, wrap the sensor wires, using the same stretching technique used doing the LEDs. Leave the last 1.5" bare so there is no tension near the Trinket.
Cut a long piece of green wire and thread it through a mounting hole on the sensor, up through the center of the bundle, looping it near the top around a branch. Then, feed it down to the sensor's other mounting hole. It should hang just shy of the longest branches. Twist the wire to secure it.
Next, take the satin ribbon and tie a bow around the top of your bundle. Allow longer pieces to dangle on the sides. The bow helps to hide the electronics. You may want to take an extra piece of the ribbon and tie it to the top of the bundle for hanging, as well.
To prepare the battery, apply a strong tape around the top of the battery to protect the wires from stress. Then, make a holder from felt. Cut two pieces a little bigger than the battery and stitch the sides and the bottom. At the bottom, leave an opening large enough for the JST plug to dangle.
Now, use a Dremel to slice each berry in half. Then, using a hot glue gun, attach the berry slices, sandwiching the LED sequins. The idea is to use as little glue as possible to ensure that the LED can allow heat to dissipate. If you can't get hold of a Dremel, you can try getting opaque beads from a craft store, or experiment with little globs of hot glue applied to just one side of the LEDs.