DANCING: Smart guys find too much dancing interferes with romancing. It saps the gal's energy and their own; sobers her up if she's had a few; makes her miss the drinks she'd consume if she were sitting at the table. But, if you'd rather dance than progress, New York's the place for it. Almost all its 1,500 cabarets present dance music; there are dozens of dance halls where you can go; and the Y's, churches and other social organizations throw hops on the slightest provocation. But, unlike smaller towns, there's neither cocktail nor lunch dancing here. (Revolting thought--dancing at lunch time.) But dinner and supper dancing: How can you miss it? If you haven't a partner, any dance hall will supply you one at a small fee per dance. Or you can easily pick one up, as unescorted ladies are permitted in all the halls, usually at a reduced fee to encourage attendance. If you can't dance, you will find hundreds of studios in the Classified directory, guaranteeing to teach you in from five to ten lessons. You will find some of these studios (especially a number in old brownstone houses on the West Side) sell more than dancing instructions. It's up to you to feel your way. If you're a swing addict, consult the newspaper ads for the places where that kind of band is playing, usually at a hotel grill. Club bands play mostly rumbas and sambas, with a few fox trots and hardly any waltzes except at the dreamy hour, after 3 A.M. New Yorkers are not jitterbugs. Most clubs hustle jive addicts off the floor. TERP TIPS: You dames with wide circumferences should not rumba. If you must, please don't quake below the equator. Don't shift your right hand up and down her spine while dancing, like a chiropractor or indecisive sax player.... Don't be a floor hog.... Don't grab the girl around the waist, hiking her dress up by inches. (Why not? That's why we sit at ringsides.) Don't ask the band leader to play a conga unless you want to be spotted as a square-head. When the band plays a rumba or samba, if you can't do it, remain at your table instead of trying to dance a fox trot to the complicated rhythm. New York is the only city where a large part of the dance program consists of rumbas and sambas. (In the East Side clubs they form the major part.) Never chew gum when dancing--but if you must, do it in time to the music! Most clubs feature two bands with continuous music, whereas small-town cabarets operate with one, which usually plays a set of three tunes, then 10-minute intermissions. So it is suggested that when you ask a gal for a dance in a New York club, you release her from your clinging embrace after a maximum of 15 minutes. Though the music goes on forever, the endurance doesn't. * * * * * DRUGSTORES, ALL NIGHT: Lexington and 49th; 66th and Columbus; Seventh and 52nd Street; Seventh and 51st; Broadway and 50th; 47th and Broadway; Seventh and 50th; Broadway and 44th. * * * * *