A pen/pad was more or less required carry when in the Army. One problem was the pen was borrowed and not returned. Here is my trick.

Carry two pens, one to use, one to loan. The loaner pen has to have a cap. When you loan the pen, don't loan the cap. If you keep the pen, you get a nice stain.

Also, instead of a pad, I carry 3x5 cards with a clip holding them together. For that matter, I carry business cards I can write on the back of.