Arm balances are really good at developing upper body and core strength and also hip flexibility. They are also fun to learn!
Here is a good little video, link below, demonstrating two arm balances that I am currently trying to learn.
Even though the final expression of the pose is advanced, the video does include some helpful preparatory poses to work towards the final pose.
These poses should be carried out within a good hip opening practice so the hips and the body are well warmed up.