Thing one: Include the ball band with your present. The ball band or tag holds all the information from composition to care (from "100% alpaca" to "handwash, lay flat to dry, etc."). Since you may be one who keeps the bands and tags or you may find that the care symbols are too hard for a lay person to interpret, you could copy down the information on a 3"x5" card or a decorative tag.
Thing two: You could become less subtle and include some wool wash with your gift. We have Eucalan brand in 3.3 oz at only $4.00, which is a small price to pay for some peace of mind. If you have a lucky individual whom you plan on knitting or crocheting a lifetime worth goodies for, then you may want to invest in a large bottle of Eucalan or Kookaburra. These rinse optional washes are almost easier than doing the regular laundry: fill a sink with cold or look warm water, add an appropriate amount of wash, insert fiber item, let soak for 20 mins., and lay flat to dry.