Don't overwater. No matter what type of orchid you have, you will almost surely overwater it. Some orchids need to dry out completely between waterings. Some need to be kept moist, but not wet. On average, water your plant only once every five to 12 days. If you think it needs water, mist it with a spray bottle.
Provide indirect sunlight. Your orchid should have bright green leaves. If they're dark green, move the plant to a spot with more indirect light. Putting the plant in bright sunlight could cause black sunburned spots to show up on the leaves. If the leaves take on a red tinge, they're getting too much light.
Add fertilizer once a month. Use a fertilizer specifically formulated for orchids and follow the directions. Don't think that using more will make it look better. You will just burn the roots and damage your plant.
Enjoy it. No matter how long it lasts, the orchid will be there longer than cut flowers. Enjoy it no matter what and try your best to keep it healthy and vibrant. When in doubt, orchids prefer abuse to careful attention. Leave it alone if something starts to go wrong. Come back in a few weeks and try again.