Find a small wooden box with a lid that has a transparent panel in the lid. My box had a thin wooden panel so I had to carefully cut out one end to remove the panel. Remove all the hardware. Stain and finish the box. Cut a piece of plastic from a CD box to replace the wood panel. Reassemble.
Program the Digispark and temporarily connect the servo to test the software and servo. I had a batch of 5 identical servos. Two of them rotated contuously when the Digispark was reset. The other three worked fine. One of those three was very jittery. I thought they were cheap but buying five to get two working is not a bargain.
Test fit all the components in the box to find the best arrangement. Cut a piece of strip board 8 rows wide and up to about 25mm long that will fit flat on the floor of the box. The strip board will act as a bus to connect to the header. I placed the trace side up so I could solder directly to the traces. You may be able to prewire the board in a more conventional manner but then you would have a challenge soldering it to the header.