For a good shoulder work out I like the "Over head clap".
Start position arms are parallel to the ground and straight out to your sides. Then, keeping your arms straight raise them above your head and clap then back down again.
do 200 of those. You'll love it....
Then do the front claps. Start position same as above. Then, keeping your arms straight and parallel withthe ground, clap to your from. Do 200 of those.
You won';t be able to eat without help after that.

If you do the exercise with "4counts" then half the repetitions I mentioned. Simple arm weight will give you the resistance you need.
Tim