We have all heard the phrase, "Keep it Simple." The tools I use for my personal painting and the workshops, are simple and cost effective. I use inexpensive brushes, tempera paints and heavy paper rather than painting canvas. The use of inexpensive supplies will take away the concern about having to conserve the supplies due to cost, and takes away the uncontrollable belief and feeling of having to be perfect. The use of more simplistic tools helps to keep the creative in a mode of play rather than being concerned of what the end result looks like.
I keep the number of brushes limited to 3-4: the suggested sizes are rounds, 12, 8, & 4.
I also suggest that you limit the number of paint colors, 6-12, when you first begin I use tempera paint as it is water soluble so the clean up is easy and chemical free, and tempera has a quick dry time. I like to you DickBlick tempera paints as they tend to be a bit thicker in consistency. Truly any tempera paint will work.
I use Bristol Vellum 100 lb. 19 x 24 paper. If the size of the paper seems a bit daunting, go with a smaller size. Also, if your creative space is smaller, then the smaller paper size may work better for you. The Bristol Vellum is a thicker paper and will handle the paint and dampness better than basic sketching paper.
You will also need a container for water, paper towels, masking tape, and something to cover your floor if you are concerned about paint drips.
You don't need an easel or fancy drawing table. If you have those things great, but don't run out to buy any more tools/supplies. You can paint almost anywhere when you keep the tools simple.
I can not stress enough that you do not need to spend a lot of money on the supplies/tools that you will being using. All of the supplies listed above can be purchased at Micheals, JoAnns, or on-line, or at your local arts stores like Dick Blick or Jerry's Artarama.
Keep it Simple & Don't spend more money than necessary!