Lighten Up - We are Children
Our tendency to notice differences makes it harder for us to discern how similar things actually are. Thus with we end up making a mountain out of a 'similar' mole-hills. Lofty 'adult' notions of 'chi' may create mental images which hinder just being natural. As 'adults' we become terrified of making mistakes. What is the difference between an adult and a child? Children know they are playing a game; adults believe the game is real... so whose the 'child'. Seeing ourselves as children, regardless of age or experience comes closer to how we actually are than notions of who we think we are, or wish we were! Why is this important? If we see ourselves as children we lighten up and give ourselves a little more slack.

Be patient with yourself!
Plan to spend a few years to get the general sense of what to do. You'll have a whole lifetime to work out the details. Thus, if you get a loose sense of the movements... enough to go through the motions, more or less, you can get a feeling for it. Then, little by little you will become more aware and coordinated in your movements. There is much too much emphasis on doing it 'right'. If our parents emphasized 'right' when we learned to walk or talk, we would probably be doing neither today. Relax, take your time and make plenty of mistakes!

Learn Tai Chi with Another Person
It is helpful to learn Tai Chi with another person; you can check each other out, even if you are both rank beginners. Of course this is especially helpful if you are not learning with a teacher. You can also have your Tai Chi partner watch the video while you do the movement, and he will attempt to notices what you're missing. At some point you could also video tape yourself doing Tai Chi and upon playback you'll notice all manner of things to 'touch up'.

Sing Tai Chi
You might say Tai Chi is a 'body song', thus do it as you would sing a song. A song has words, phrases, and a melody which contains it all. Once you know the words to a song and its melody, breathe brings it to life. The same goes for Tai Chi, only takes a little longer to learn the 'words and phrases', i.e., the individual movements. I suppose the sense of flowing emptiness in Tai Chi is its 'melody'. And breath is breath. Noticing such similarities with other, seemingly different activities can deepen knowing.