I deal with this too , although not quite as extreme . I ' m in my mid 20 s and probably would be mistaken for collegeaged everyone at work thinks I ' m an intern , super annoying . I think it ' s good that you recognize that you don ' t want to go to the other extreme and end up looking like a business woman . You probably already have a sense of what kinds of clothes look younger , so of course you ' d want to avoid juniors sections and so forth . In general , I ' d say going for more tailored pieces , maybe erring on the side of a bit androgynous could help . Think pencil skirt rather than skater skirt . Keeping colors somewhat neutral or jewel tones like maroon or emerald green , that read as more mature . Solid colors and basic patterns , and avoiding prints like polka dots or certain florals that could read as juvenile . Keep in mind wash , material , and other details , like dark wash jeans with matching dark stitching vs . distressed light wash jeans , which look younger . Shoes and bags that read as classic and versatile . Not to say that you definitely couldn ' t do any of these things without looking young , but those things might help as starting points .