My wife has been using our stairwell cabinet drop down desk as her personal office, which has been great, but she pointed out that there was no adequate lighting. I had some left over 'LED strip lighting' from another project outside the house. All I needed to do this was:
30" LED strip lighting (bought on AMAZON from LEDWholesalers), 12V/2A power supply, and an 'inline low voltage switch'. The LED strip has an adhesive backing so it was easy to attach to the top inside of the desk. We still have some work to do on cleaning up the power cords (computers, phones, and now the LED lighting).