So in this video, I'm going to show you how I did it. First, here is a list of all the parts I used, with links to where you can buy them. All prices are in US dollars and from 2017. Prices may have changed.
LED light set: eBay ($22.69)
10kOhm logarithmic potentiometer: eBay ($1.89 for 2) or locally
10kOhm trim potentiometer: eBay ($0.99 for 10) or locally
USB wall charger: free or dollar store
2ft 4” PVC pipe: free or Home Depot ($9.13)
2x 4” PVC drain: Home Depot ($3.21)
Threaded insert: Home Depot ($2.97 for 4)
Cabinet Handle: Home Depot ($1.16)
Black plastic paint: Amazon ($5.94) or locally
IEC320 C8 power socket: eBay ($1.14 for 2) or locally
IEC320 C8 power cord: free or Monoprice ($1.88)
Knob for potentiometer: eBay ($0.99 for 5) or locally
In total, it costs $53.32. But if you decide to make a second one, the cost for the second comes down to $30.27 since many of parts you can only buy in multiples, so you already have enough for the second.
You can also buy lighting umbrellas with holders, as I did:
Umbrella holder: eBay ($2.99)
Umbrella: eBay ($2.59)
I doubt anyone will make these lights exactly as I did. I took inspiration from these two videos, so check them out to get some ideas for yourself.