Hi Lithos2 -
I feel that any day you see a bird is a “good bird day”. Of course, some days are better than others, like when you see (and, as a bonus, photograph) an uncommon bird.
Birds are driven by their search for food first and then finding suitable shelter in which to live and raise a family (not so different from every animal species on the planet, including humans
). You are lucky to have a tree outside your office window, so you may want to try hanging a seed or suet feeder and see what you get. I’ve observed that most urban birds have a routine that they tend to stick to once they find a reliable food source. It’s about every 30 to 45 minutes that they show up to feed, so if you happen to miss them just wait around a little and they will eventually return. The type of food that is available also plays a big part in what species you attract as will offering a bird bath. It’s too involved to go into detail here, but some online research on attracting backyard birds, or a trip to your local nature shop will provide you with lots of information.
Happy birding and don’t get too distracted from your work