Scanning my sketches is one of the many tedious processes I have to do as part of my creative workflow that create friction. I don't feel like doing it, ever. But it's convenient to have high-resolution scans of my drawings on Dropbox available when I need them.
Instead of scanning them on demand—when I intend to use them—I like to scan all pages of my sketchbooks as I fill them. That way, I don't stress out too much if I ever loose my sketchbook as I can create high-fidelity reproductions of my drawings with 1200 dpi scans.