Don't eat a large meal within several hours prior to wearing a corset. Eat small meals, and avoid fatty or hard to digest foods. If you are planning on lacing tightly especially, it is important that there is a little something in your intestines, because apparently they can stick together if empty. So eat lots of small meals of starchy food.
If there is any question of washability you should wear something underneath the corset to protect it. It is also more comfortable to wear if there is something protecting your skin. The more breathable and absorbent the better, so find something in a natural fiber if you can. Often I wear my corsets with just a pretty bra, so I wear a tube-top of the same color underneath, which doesn't show, except between the laces in back.
Loosen the laces until you can easily hook up the busk in front. The eyes should be on the right side of your body, and the buttons on the left.
The first couple of times you wear a new corset it is important not to lace it too tightly all at once!!! This is not just for your welfare, but for the corsets'! The fabric fibers and sewing threads can be weakened or broken by the sudden stress put on them by lacing it on tightly all of a sudden.
That said, reach around to the back, and hook your fingers through the loops (or lace ends) in the middle. It will put less stress on the corset if you pull towards the center with the laces instead of out. So pull on the loop for the right side of the corset with your left hand and vice-versa. Pull SLOWLY. You may find there is a lot of slack at the very top and bottom that you will have to work down that just pulling on the loops won't do. This is more easily done by someone else.
Lace the corset in just until you feel slight tension in the waist, and wear it that way for an hour or so, then gradually lace it in little by little this way. By doing this you will gently break the corset in by allowing the threads to slowly stretch where they need to to conform to your body. If you are extremely conscientious you may want to lace your corset in over the space of several hours each time you wear it simply for the sake of your body.
Until you become accustomed to wearing corsets go gently with the constriction. I recommend you read the link on the hazards of tight lacing to gain awareness of what can happen if you over-do it. Pain is beauty, but broken ribs or damaged organs is crossing the line! A little superficial discomfort of pinched or chafing skin, even a little bruising on the lower ribs after a few hours isn't what I would consider cause for alarm, but if it hurts more than that you may be risking serious injury.
I find that if I don't wear my corsets at least three or four times a week they become very uncomfortable and I can't lace them as tightly as I am used to doing.