Since then I've followed a willow, boxelder, limber pine, juneberry, hawthorne, chokecherry, maple, balsam poplar, and even an extinct palm tree (that didn't work out so well). After all these years and trees, I'm still at it. Seems I always learn something, often something interesting or unexpected.
I've learned that for me it's best to choose a tree that's easily accessible, and even better, in a place I enjoy. Deciduous trees are preferable to evergreens (= conifers here) because they change more through the year. But it's getting hard to come up with a new species. Laramie, Wyoming is 7200 feet above sea level, semi-arid (12" annual precipitation), and far from any moderating coastal influence. Tree diversity is limited.
Hints of things to come: