I recently got myself a bunch of elastic bands with different levels of resistance. The main reason I bought them is to use for warming up and doing mobilisation exercises before workouts.
What I like the most about elastic bands is that you can sustain an isometric contraction of the muscles which is harder to accomplish with free weights. The bands also do a great job at getting blood moving quickly into the muscles and achieving a nice pump. (sidenote: Arnold offers the most amazing description of what the POOOMPP is :)).
In the video below you will see me demonstrate what I like to call the „Sunray Exericse„. I move my arms at different angles and perform 5 reps or so at each position. Going through the angles on the circular path, it kind of creates the rays being emanated by the sun. Then I just keep the contraction steady and move my arms up and down along the semi-circular path. This is sure to activate the rotator cuff and get blood rushing to the muscles.