Do the right thing for flowering gifts. Heating vents, radiators and south-facing windows are better for people than plants, which need strong indirect light and lower nighttime temperatures. Cyclamen prefers high humidity and 60 to 65 degrees during the day. Keep poinsettias and amaryllis watered. Not all orchids are alike - some need warm nights. With the precise variety name in hand, consult the local library or the greenhouse that sold the plant.
Have a friend check on houseplants if you'll be away for a while. (Tell novices not to over-water.) For a long absence, group plants, place a full bucket of water in their midst, and fashion a tent of clear plastic over and around them to raise humidity. If there's enough light in the bathroom, a bathtub is ideal; otherwise, be aware that condensation may run down the plastic to the floor.