3. Any additional tips, tricks, or guides would be appreciated.
I assume SMD work on a Leeku PCB means you need to add RGB LEDs?
My advice: add a generous amount of solder to
one pad. Not a ball, but enough to visibly raise the pad relative to the PCB. 0.5mm-1mm or so. Using tweezers unless your fingers are immune to the heat, place the LED where it needs to be and heat the pad you added solder to
and the RGB LED leg. Get them bonded together, doesn't have to be great. Now go heat the other pads, one at a time, and add solder once they're heated. Easiest if you angle the tip so that it's touching RGB LED leg and pad simultaneously, then touch solder to pad. Should flow up.
Do your other three legs, then go back to original leg and touch it up if needed.