Hey! Most (if not all) of my illustrations are inked with Micron pens and/or a Pentel Pocket brush, then scanned into Photoshop. The primary brushes I use are from Kyle Webster’s Mega Brush Pack and these Frenden brushes (Stumpy Pencil also has some good free ones to try out). Then I usually throw a texture over them. Lost & Taken is my go to for nice free textures.
Hope that helps!