Tennis bracelets are unique by design. Authentic tennis bracelets typically contain a row of diamonds, though some newer bracelets feature any number of different types of stones. Diamond tennis bracelets usually have a protective latch that ensures you won't lose the expensive jewelry if the main clasp comes undone. Although the protective latch is designed to be helpful, it can be a nuisance to unattach each time you take the bracelet off. These latches generally come in two types -- circle and chain.
Look to see which type of safety clasp you have. A circle clasp features two loops of metal that each attach to a post on either end of the bracelet; it looks like a figure eight. A chain clasp spans the gap between the two posts if the main clasp comes undone.
Grip one end of the circle clasp and pull up gently. It should come unattached, leaving the other end still attached to the post. If it won't budge, gently place one finger underneath and lift up, applying direct pressure on one end of the clasp. Undo the main clasp and slide the bracelet off.
Take hold of one end of the chain clasp. Not every chain clasp is the same, so you'll have to examine yours closely. Some are designed like most chain necklaces with a sliding circle; in this case, press on the lever with your fingernail until the circle opens, releasing the chain. Once you have the chain clasp undone, release the main clasp and slide off the bracelet.