It's just that you were worried about it the first time and not compeltely relaxed.
Get yourself a phone that can be worked hands-free, or a headset. Have a nicely set-out table, and a deck you're completely happy with. Take time after they make the appointment but before the reading happens to settle yourself: have a cup of something hot, go to the toilet. Then lay out cards exactly as if they were there, and discuss teh fall of the cards exactly as if they were there. If you would normally pick up a card at a given stage to show it to them, pick it up anyway, even if they can't see it.
If you're a technophile and have a gee-whizz-yew-beaut phone that does visuals and they do too, prop the phone up on something so they can see at least a part of the spread and how your hands are moving as you're talking.
You'll get comfortable with it. distance is no object. I've read by email for people that I only knew as nicknames on the internet, with not even any voice contact. It works, What isn't working for you, is your trust in teh process. Work on that, and the readings will be perfectly fine. Remember: Tarot is non-physical, it crosses the universe. Distance it no object to it.
