Here are a few consumer tips for those weighing spring or summer journeys to New York City and side-trips to the Broadway theater:

Go, if at all possible, during the week, when box-office prices average about 20 percent less than on weekends, and tickets are available for all but a few extraordinary hits (the exceptions just now are "Sugar Babies," "Annie" and "Evita").

If you are determined to see a sellout show, buy your tickets well ahead of time through Ticketron outlets here.

Once in New York, check the TKTS booth at 47th Street and Broadway for same-day half-price tickets. The booth opens at noon on matinee days and at 3 p.m. for evening performances.

Even if the show you want to see is said to be a sellout, check for cancellations about 45 minutes to an hour before curtain time. There are usually a few seats available on weekday nights to all shows. (Some theaters sell standing room, too.)

Explore package hotel-theater plans. The Warwick, the Sheraton City Squire and the St. Moritz are three hotels with such plans. For more information, call or write the New York City Convention and Visitors Bureau, 2 Columbus Circle, New York, N.Y. 10019.

If you want to avoid shows that are eventually bound for Washington, avoid these: "Children of a Lesser God," "Evita," "I ought to Be in Pictures," "Sugar Babies," "Sweeney Todd," "They're Playing Our Song" and "Whose Life Is It, Anyway?"

If you want to hear voices coming more or less from human mouths rather than wireless mikes and speakers, avoid the caverns known as the Uris and Minskoff Theaters (where"West Side Story" and "Sweeney Todd" are the current attractions).

If you like old-fashioned theater architecture, and theaters with rich histories, try the Lyceum ("Morning at Seven"), the Music Box ("Death-trap"), the Booth ("The Elephant Man"), the Shubert ("A Chorus Line") or the Mark Hellinger ("Sugar Babies"). The Lyceum, one of New York's oldest and least altered theaters, may be the prettiest of them all.