In the category of "waste nothing", here's a handout I wrote way back when (over a decade ago) that I use for my standard graduate seminar class on How to Read a Research Paper. Others have found it useful enough to use it (with permission) rather than construct their own. If you like it, feel free to use it, and modify it as you like. I even have the Latex around; just ping me if you want it.
There are other pages and places with more advice on the topic, so you might want to look around. Searching on phrases like How to Read a Research Paper (and other variants, like How to Read a Technical Paper) will yield plenty of pages. I like the "What to Read" section at the bottom of this page from Jason Eisner -- creative Web search and forward/backtracking references are, I think, often underappreciated skills.