This one is easiest if performed in a circle.
Shake the right arm for 8 counts... you could add music or simply count to 8... then the same with the left arm. Follow this with 8 counts to shake the right leg and finally 8 counts to shake the left leg!
Once they have the pattern repeat it without any pauses when changing from limb to limb.
Then repeat the whole thing but with 4 counts each time... then again with 2 counts... and you can even do it on 1 count!
Then, of course, you can repeat the whole thing but count faster!