Start with a block near your front ankle with your feet wide apart and the front leg turned out 90 degrees. With both shoulders against the wall, bring the front hand down to the block. Notice how much harder this is than when you do Utthita Trikonasana in the middle of the room. Why? Because the wall tell you the truth. The wall has the added advantage that you can't stick your buttocks out. More truth.
If you notice that my top elbow is away from the wall, that is a result of the shape of my arms. For more on carrying angle, check out the wonderful interview of George Purvis on the Iyengar Yoga in Houston blog. He really is all kinds of awesome.
Now for some more wall truth. Utthita Parsvakonasana. I remember when my teacher, Karuna Nicols, first taught me this. I learned that my back leg lies to me all the time. My leg tells me it's straight, that it's working hard and I'm pushing that thigh back enough. LIAR! The truth of the wall will set you free.
Here's how to do it: place a block behind your back thigh against the wall. Foam blocks are a little easier here, but who wants easier?
That was exhausting, so let's lie on the floor. It's great to be on the floor and practice standing poses. The floor is even more accurate than the wall. Plus you can hold standing poses for 5 minutes without a problem. Floor poses are great for those that need more flexibility.
First let's try Utthita Trikonasana - the supta (reclined) version. Place both feet at the wall. Put your front foot on a block. The foot is on a block to have the correct alignment of the front foot to back arch - if your foot was on the floor, the leg alignment would be heel to heel. Lean on your front leg, so you can turn it out 90 degrees. I usually get on my entire side and roll out. Extend your back leg back so that foot also touches the wall. Bring your front hand down to the block and roll out, so both shoulders are on the floor. The floor, being a flat surface, will show you how much you can turn out. It will also show how high your foot block should be. See how my fingertips just touch the block? Something would have to give way to get my hand all the way to the wall.
You should stay long enough that a cat falls asleep in your armpit.