Golden-crowned kinglets are pretty common, but they tend to spend a lot of time in the canopies of the conifers, so they can be difficult to get a good look at. I occasionally see them down lower (on a couple of occasions even on the ground) but even when that occurs and I actually have my camera, it has been difficult to get a picture.
Golden-crowned kinglets seem disinclined to spend any significant time in one spot. They flit about, constantly flying from branch to branch looking for the little insects they eat as food. I have heard that during nesting season, they aggressively defend their nest. So if you happen to find yourself getting chattered at by a little kinglet during the spring or summer, you may be closer to the nest than he prefers. That might provide an opportunity to get a photo, but so far I have never knowingly witnessed a kinglet defending territory in this way.
Earlier in the week, I noticed a small loose flock of kinglets, chickadees, and possibly a brown creeper foraging on some smaller trees not too far from our house. I was fortunate enough to get a few reasonably decent photos; better than any I had taken previously, anyway.
Still, I think I missed more than I got.