One picture may be worth a thousand words, but in today's decorating climate, the frame may be more valuable than the picture.

The Professional Picture Frames Association reports an increase of interest in elaborate frames as well as a trend toward framing everything from needlepoint and family heirlooms to mementoes and memorabilia.The Lazarus department store in Columbus, Ohio, recently opened a frame shop next to its stationery department to handle the increased interest in framed photographs as a decorative accessory.

A new book, "Displaying Pictures and Photographs," offers guidance on aesthetic and practical issues in framing, arranging and lighting art works.

Caroline Clifton-Mogg, co-author of the book, with Piers Feethman, says selecting the right frame is not a simple matter; each instance is unique. Frames can not only show off the art work to best advantage, but can add luster to insignificant works.

Until recently, it was considered most appropriate to hang pictures against a white wall. Now, pictures may hang against patterned wallpaper or a decorated and colored wall surface.

Busy backgrounds, however, need strong pictures and frames. Choose pictures that complement the decorative period of the room, or introduce a color of the wallpaper in the mat or frame surrounding the artwork.

For the best arrangement for framed artwork, says Clifton-Mogg, consider the style and mood of the room or area in which the work will hang, as well as the relationship of the mat and frame to the rest of the decor.

In a small room with low ceilings, for example, don't hang several large pictures close together. Dark walls are good backdrops for monochrome works, line pen and ink drawings, or strong linear architectural prints.

When hanging pictures over or near furniture, relate the frames and subject matter to the furniture, perhaps aligning them in a symmetrical arrangement by matching the two woods or by tying the mat to the upholstery color.

If your double bed lacks a headboard, hang a large picture or group of pictures above the bed. Make sure the edges of the picture don't extend beyond the edges of the furniture beneath it.

When a picture is hung alone, it should be at eye level; when it is part of a group, choose a darker, broader or heavier-looking frame to give extra weight to one element.

A group of framed artworks may be improved by exploiting an interplay of shapes, says Miss Clifton-Mogg. Introduce a circle, oval or lozenge shape among the squares and rectangles for a surprisingly dramatic effect.

Framed family photographs often are displayed on a table or mantel in a mix of old and new frames.

Photographs and small works also are hung in hallways and staircases.

The Professional Picture Framers Association offers these tips to protect the artwork:

- Use acid-free matting and adhesives to prevent deterioration.

- If framing needlework, have it mounted so it can be removed without harming the needlework. Lacing is one such method.

- For three-dimensional objects, such as medals, use ultraviolet glass to protect art from the sun's rays.