This is a posture I love. I have a fond memory of performing it poolside at a resort in Zion National Park on a beautiful day in July. Now, even when I'm attempting it in my bedroom in the middle of winter, I can think of that wonderful experience.
Bird of Paradise is set up in a side angle pose. If you cannot bind in side angle, you should not attempt Bird of Paradise just yet. First work on opening up your side angle posture in order to allow your hands to bind, as pictured below.
Once you are able to bind your side angle, you can work on shifting your weight and eventually lifting your bound leg as you stand.
In order to transition from bound side angle, bring your back foot forward to meet the front while holding your bind. From this posture, shift your weight into your unbound leg so you can lift the bound leg as you stand. Take your time and find balance with a strong core. You may keep your bound leg bent or extend it as your hamstrings allow.
When performing Bird of Paradise, be sure that you are working on squaring your shoulders and hips to the front of the room. If you find your posture is compromised, meaning, your spine is curved or your shoulders are hunched, then you are not yet ready for this pose. Staying open is key to success.