For the quick study, I like to use 5" x 7" canvas panels. The Fredrix ones shown are one brand, but there are many.
These are canvas wrapped around heavy cardboard and then primed with gesso so they are all ready to paint on. They are inexpensive, which is key to feeling free to experiment! You could also use stretched canvas, canvas sheets, or even watercolor paper with a coat of gesso on it.
I'm using one flat brush - about 3/8" wide. It is a synthetic brush, not too soft. You want to be able to push that paint around!
The paints I'm using are Golden Brand Open Acrylics. Open acrylics differ from the regular ones in that they stay wet a lot longer. You can use them more like oils. They blend nicely.
I usually use regular acrylics because I prefer the ability to layer the paint, but for these studies they work well. You can use regular acrylics as well. In fact, I encourage you to use what you have, so you don't worry about the cost! The methods I'm using in this demo, though, will work better with the Open acrylics or oils.
These are the colors I used for this study. Feel free to substitute - My goal is to show you a method to paint the quick study, so that you can apply it to many, many subjects.
Other supplies: paper towels, water container, easel (you can paint flat on a table as well, or roll up an old towel to prop up your canvas to get rid of the glare of overhead lights)
Feel free to leave a comment if you have any questions!