Some craft fairs coming up . . . The Federated Woman's Club of Crofton, Md., sponsors its 6th annual arts and crafts fair this coming Saturday (rain date, May 5) on the village green in Crofton. About 60 artists from the Baltimore Washington area plan to be on hand.

. . . The Flat Iron Arts Center in Hyattsville also is holding an arts/crafts event this coming Saturday and Sunday around its studios across from the court-house in Hyattsville. Admission is free (779-9786).

. . . And Cabin John Pottery holds an open house with stoneware and porcelain by Judy Kogod, also next weekend. The studio is at 7687 MacArthur Blvd. in Cabin John (229-7530).

. . . Classes care of the American Crafts Council . . . Mary Lee Hu shows how to make forms from wire by twisting, wrapping, weaving and knitting it the weekend of May 5 and 6 ( $45, non-members).

. . . The weekend of May 12 and 13, Ruth Duckworth demonstrates her methods of making small and delicate objects in stoneware and porcelain ( $45, non-members).Duckworth also gives a slide lecture May 11 ( $4, non-members).

. . . May 11, Luba Krejci shows contemporary lace making using ancient Czechoslovakian techniques ( $25, non-members). She delivers a slide lecture at the Textile Museum at 8 p.m. the same day ( $4, non-members).

. . . Marcia Lloyd teaches a class in leatherwork, demonstrating the use of cuir boulli , or wet-formed, technique, May 12 and 13 ( $45, non-members). Lloyd lectures at the Renwick May 11 at noon (no charge).