1. I use cheap paint brushes.
A Little Raggedy Artist Pam Story Time:
2. Most of my references are photos from Pinterest and other sharing sites.
Important Caveat Below!
Be careful of using photos or artwork from Pinterest if you publish any work derived from pins, however. It is no big deal if you only use them for sketchbook works, but if you post a finished piece online that is too much like another's work, you might get a nasty letter from someone's attorney. Also, be aware that just because the artist is referenced in a pin, it does not necessarily mean that the artist gave permission for the pin to be shared.
To be clear, referencing an image to understand the physical characteristics of the subject, like the shape of an object or the position of a person's body during a specific movement, is perfectly ethical. However, copying an entire image or part of that image might violate copyright rules. It's complicated!
The best way to avoid issues like this is to use images that are on the Public Domain (PD) or released into the Creative Commons (CC) for others to use. Public domain items have no limitations for use. You could print off an image from the PD and sell it with no repercussions (don't be a jerk, please). When using CC resources, you have to consider the licenses of the items. Some allow you to do anything you want, while other licenses limit conditions of use (i.e. some require simple attribution, some do not allow commercial use, etc). Please read the information at the linked sites as I have barely touched on the rules here!
As I prepared this post I realized that there was more to discuss within each "confession" than I had anticipated. I wanted to present helpful information, as it is the least I can do to repent for my craven acts. Maybe I have earned a little redemption from this post, but to save my artist soul I must complete a few more posts detailing my other transgressions. Are you an artsy rebel or do you play by the rules? Let me know in the comments.