This is the easiest way I've found to make brining a part of my dinner prep because it doesn't make any extra dishes, it's simple to do and you still just recycle the jug when you're done.
All you need is a milk jug, a funnel, and some kitchen scissors.
Brine the meat in the jug
Thaw and flatten meat. I like to try and get the meat to be of similar thickness so that cooking times are similar.
Put the water, salt, and whatever else you like in your brine into the jug, put the cap on and shake it up. The basic brine in the picture is 1/4 cup of salt, 1/4 cup of sugar and 1/4th of the gallon jug with water. The ingredients that people use vary considerably, but I've found this is effective for my primary goal of getting a juicier piece of meat on my dinner plate.
Cut off a piece of the jug and put the chicken in.