Five WS2812B-3535-style addressable RGB LEDs in a daisy-chain row with per-LED 100nF decoupling, a 330Ω data input resistor, and external 5V/GND/DATA pads.
Hand-solderable 9V battery-powered red LED blinker using a 555 timer in astable mode, an on/off switch, and through-hole support components for approximately one blink per second.