Looks like about the right amount of solder, though you are probably just being too cautious about over heating it. Ironically a little hotter soldering iron has a smaller HAZ (heat affected zone) than a colder iron just due to the time required to heat component, the solder, and the board.
Make sure you clean your tip and are operating hot enough. The solder should flow and spread out covering metal not protected by the soldermask.
Your joints look cold and have insufficient wetting. Should be able to apply flux (or just a tiny bit more rosin core solder) and reheat. It should expand out and get shinier.