For your first chains, don't choose thread much finer than #1, and pick a cotton thread with a smooth, even surface. "Speed-Cro-Sheen" and "Double Quick" are readily available, adequate, and come in assorted colors. Don't get thread much heavier than heavy crochet thread. Macramé cord is good for demonstrating, especially to a roomful, but cord is awkward to learn with.
You need only half a yard of "shuttle" thread and a yard or two of a different color for ball thread. Don't bother with a shuttle.
If you are left-handed, you are probably asking yourself whether you ought to hold the pictures up to a mirror. Reverse the motions shown only if you have some injury or inadequacy in your left hand. Tatting uses all the fingers of the left hand, but can get along with only two or three on the right, and all of the delicate adjustments are made with the left hand.
Turn to the pictures in "How to Plain and Purl," or stand behind someone who knows how to tat so that you can see his hands from the same angle that you view your own. Don't do both! There are a zillion ways to tat; the odds that your teacher and I match aren't worth calculating.
Make a plain, then a purl, then a plain . . . .
Note that when you make a stitch, you first tie the shuttle thread in a half hitch over the ball thread, then straighten the shuttle thread and thereby pull the ball thread into a half hitch around the shuttle thread. Then you pull on the ball thread to snug the loose loop down into a knot. Snug, but not too snug. You don't want to strangle your shuttle thread. If it is difficult to pull the core out when you are through practicing, your knots are too tight. If the knots are loopy and uneven, they are too loose.
If you frequently pull the core out before you intend to, tie the end of the shuttle thread around a paper clip or other small object. Use a ring hitch (see Illustrations of Knots) so that it will be easy to untie.
>>..illustration of paper clip here.
Knot and untie the two threads until you can do it easily.
A word of warning: tatting is a physical activity. You're doing it to relax, to be sure, but the movements you are making are movements your muscles have never made before. The worst charley horses I ever got were earned while sitting down and leaning back -- if you feel yourself getting tired, STOP!
Remember that another word for charley horse is "repetitive stress syndrome"; you can set yourself up for Feldene, physical therapy, and permanent damage if you keep going after it starts to hurt.
If you tend to tense up while concentrating, get up and touch your toes every now and again, or at least shrug your shoulders back, hunch them up, and let them drop into a relaxed posture.