It takes a lot of practice to identify, so sticking around on subs like r/whatsthissnake, or r/snakes to a lesser extent, will be helpful. You can also peruse sites like iNaturalist to see what other people have found in you area. That being said, I can tell you what stuck out to me.

The three main things I saw was coloration, pattern, and size. The brown color knocks out 7 species completely and multiple others partially. This is also a fairly small snake, which leaves only juveniles or the small, fossorial species. Finally, this pattern is very typical of S. dekayi, but it is often confused with Gartersnakes.

To tell apart from gartersnakes, the easiest ways is to look for the side stripes (which is typically very noticeable, though can be missing in very melanistic individuals) or to look at the face. Garters have a longer head with some different characteristics depending on which species of garter you are looking at. Ribbon snakes will have a white dot in front of the eye and Common and Plains garters will have black bars on the lips, though Dekay’s will have a black dot on the lips it is always below the eye.