How to use CFrame to animate arms/legs?

I've seen free models and people using CFrame angles to animate arm movement and stuff. For some reason when I try it, all it does is move the arm according to my arm in a split of a second instead of seeing it MOVE. Its quite weird, can anyone tell me?

for i=1,30 do
part.CFrame=part.CFrame*CFrame.Angles(0,1,0)
end

That works, but you cant see the part rotate. It just...rotates.

For one, you did not have the For Loop sleep during the rotation. Insert a wait() after the part.CFrame so that you can see your arm move.

I would recommend that you learn about Euler Angles and Radians, for animating using CFrame requires a good amount of knowledge on how to rotate parts in certain directions by a certain offset.