Hi bmlyeryk,
Everyone's posts are right about this.....
Feeling you have to do everything right when doing something the first few times is normal, so feeling you've made too many mistakes is also going to be normal. Usually it's the result of the mind overacting. Once you practice you will feel comfortable doing it and will feel free to do it in your own way and still feel you're doing it correctly.
Wondering if you can't move if something itches, if you're breathing the right way, or if you are in the alpha state, might actually push you out of a relaxed state, simply because of the slight stress those thoughts cause.
So a good way to approach this is for example, don't worry about them- don't be afraid to scratch yourself or move when you want, it won't affect your altered state. Think of the times when you were drifting off to sleep and you frequently turned over or moved and still drifted off to sleep rapidly.
The same would be for how you position yourself- make yourself as comfortable as you can if you like... practice different eye positions and use one that's comfortable for you....you are doing it correctly.... you're not doing it correctly when you're worrying too much
if you're doing it correctly
The real progress comes from how much attention you put on visualizing and thought....
Here's one thing that really helped me with this... before you practice again, you can strettttch each part of your body for about 10 seconds each, from your feet up to your eyebrows. By the time you start, that should make your physical body feel very relaxed and limp-like...
Take care and good luck...