I've been known to use a few pencils in my line of work, and Slate has a nice analysis of whether mechanical or old-fashioned wooden ("manual"?) pencils are more sustainable. (Note that the article is written with a bent toward forgetful 12-year-olds; although I am slightly older, I am no less forgetful.)
Pencils are one thing; but what really disturbs me is the volume of paper my industry consumes. From the drafting vellum (aka "trace," "flimsy," and "bumwad") we begin our concepts on, to the infinite number of preliminary designs and construction plan documents we ultimately print for our clientele and contractors, to the orders we fax back and forth with our plant nurseries, to the proposals and invoices and business cards and other administratia that are an integral part of our work, we murder an obscene number of trees for folks who supposedly value trees.
(Automatic A+ to anyone who calculates, including proofs, how many trees must die for a 24" x 36" sheet of bond paper.)
Sure, I try to do my part: I've migrated, reluctantly, to CAD drafting and 3D modeling; I render my drawings at smaller sizes and enlarge them digitally, thereby using less paper (and less marker); I spec recycled paper for my plan documents; and I email PDFs whenever I can instead of printing hard copies of proofs, prints, proposals and the like. But the fact remains, we're a paper-intensive business. Any suggestions for how I can reduce my use?