Strapless styles vary a lot in how they stay up; look for grip elastic or lining and read reviews about whether they slide down. Polyester satin is common — looks shiny but can be less breathable and show sweat marks easily; silk satin feels more luxurious but costs more and usually needs dry cleaning. Fully lined dresses look richer and less sheer than unlined ones — especially important if you plan to wear it without a slip.