Flux, liberally applied, is the sudo of soldering. It lets you force your will and make the solder do what you want. No one ever uses enough. I always have either a pen with a felt tip, or a syringe of chip quik.

It (a good proper flux) is what most people are missing when they struggle with SMD, the flux makes the solder almost magnetic and it jumps perfectly to the pad and the component. Mess up, make a bridge or bad connection? Add more and wave the tip through like a magic wand. Poof. Fixed.

Thanks for coming to my Church of Flux presentation.