When projects involve lots of small fiddly bits, moving parts, and lots and lots of wires like this one, it can get tricky. In order to make success more likely you will definitely want to test your components at each step of the process, so you don’t spend hours of time soldering only to find that it all mysteriously doesn’t work. Testing at each step means you’ll catch any shorts or mistakes early. Plus you get to see your lights come on right away which makes the whole process much more fun and satisfying