You can buy an official Blackwing Pencil Point Guard for around $14.00. They are lovely and well-fitting and appropriately beautiful. Alas that level of stationery nerdery is too much even for me.
I have a Blackwing pencil, which I love, and carry around with me in my sketchbook satchel all the time, and its point is forever getting dulled, and peeking through the satchel, in the most annoying way.
The solution? This 3D model of a point guard, which loosely approximates the official model, just enough to serve my purposes. Thirty-three minutes on the 3D printer and a little bit of sanding.