I've recently had the need to do a little bit of soldering and what I found worked is to:
1. Warm up the pin, but don't try to get it hot enough to melt solder
2. Touch the solder to the iron to create a ball (looks like what you have)
3. Melt the ball and poke it down to try to get it to catch surface tension on the board and switch into a Hershey's Kiss shape

Not claiming to be an expert by any means, just sharing what I recently learned since it's still fresh in my mind.