Tight hips can be the numbing nemesis if you're following along with the most limber of yoga teachers.
Why don't my legs jackknife into flying pigeon pose? It "only" requires the right foot wrapped around the left triceps with a slow weight change forward on 90-degree bend elbows to float the left leg up to hover, all while not falling forward to break your nose. If you don't have a solid pigeon pose on the floor, the flying one will present definite challenges (at least to this yogi!).
Before you can run, you must know how to walk, right? The same mentality applies to complicated yoga poses that tax the hips. Many yoga poses are for the spaghetti limbed with perfect hip mobility. Not so easy for those working on rigid hips with big asana ambitions.
As someone who works daily on hip mobility (an anatomical challenge of mine since coming out of mama's womb, I'm told), here are some good poses to gently work with what you've got: your prized body—treat it as a child warrior. Don't talk mean to it; it's all you've got.