Shelving Matters

I've got a fair number of non-fiction books. Up to now, I've shelved them purely in alphabetical fashion (last name of the author). Recently I started pulling out books on observational astronomy, because I might be out observing in the backyard and come in to pull a book down off the shelves. It made it easier to group all the observing books together.

If certain things come to fruition, then I'll need a better way of shelving my other non-fiction books. Shelving solely by alphabetical fashion means that books on a certain subject might be hidden (out of sight, out of mind). So I'm thinking of adopting the Dewey Decimal system or something equivalent. Anybody out there do anything similar?