Here’s some sets of photoshop brushes you may find useful. I’ve done my best to point to the original sites of the creators where possible. I tend to use the stumpy pencil and the digital inking brush from Geekasaurus-Rex almost exclusively these days.
Pencil Brushes
Awesome Photoshop Pencil Brush
Ink Brushes
Inking Brush by Geekasaurus-Rex
Simple Inking Brush for Photoshop
Misc Brushes/Sets
Nagel Brush Series (This is a series made up of about 43 different sets. Sets 1-39 are collected here while you can grab 40, 41, 42, and 43 separately)
Custom Brushes from idrawdigital