Cover your surface as normal and then take a stiff brush (a hard toothbrush is good) and rub gently on the surface. The harder you press, the greater the effect. If the effect isn't as strong as you'd like, try dabbing lightly at the surface with a damp cloth and then brush again.
It's probably a good idea to practice this technique on a test drawing first! It's also a good idea to only use this technique on heavier paper. Thin papers such as copier paper will quickly wear through.
