If it's a moth orchid (Phalaenopsis), I would prune off the bloom spike just above the scale that's below where the lowest bloom was. Often, you will get one or two new spikes from that point. Keep watering and feeding as normal Any other kind of orchid, I would prune off the bloom spike where it comes out of the bulb or main stem. New sprouts will then appear from the base, and these will grow into the bulbs or stems that will produce next years flowers. Orchids like bright indirect light or filtered sun--lack of light is the most common cause of failure to rebloom. They like regular light feedings. And most of the species like to dry out somewhat between waterings. Humidity helps, also, but most don't need as much as their reputation suggests. Cymbidiums and Miltonias bloom best in cool conditions (60-70 in the day, 50-60 at night), but most of the rest do just fine at room temperature or a little above. Good luck!

thanks Tug this will help me as well I've " rescued " one thats finished flowering and hope to encourage it to flower again

P.S Ive just nominated this answer for Goypedia

Thanks, Pam!