Waist coat (sometimes called a vest or a vestee) are always trendy, I don't think they will ever go out of fashion. They are so flattering to the Male/female figure and come in all sorts of colours, shades and materials. I have about six different ones myself! The Best part is , It compliments You on both Denims & Formals, & even with the Blazers. Waistcoats never looked so good! If you are looking for an ultra-trendy waistcoat, don't miss Van-Heusen or Louis Philippe.
My suggestion :- Always stitch your waist coat for that Perfect fit.