I only wear my semi-formal outfit these days (black tie with dinner jacket, matching trousers with stripe, cummerbund, hand-tied bow tie and dress shirt) for the BEC Dinner, which I think is suitably counter-culture (although many/most do dress up well). It is immediately changed out of, of course, at the following party (and I typically end up in gold hotpants or less)...
I must admit to my shame that my bow tie is an adjustable model. I did used to have a proper dress shirt with detachable collars (wing-tip, another faux-pas for black tie purists of course) and screw-on buttons but the collar went yellow with excessive starch/ironing, and getting your detachable collars laundered is difficult in these modern times (i.e. not the 19th century)
I do have a white tie set as well, purchased cheap off eBay (tailcoat, white bow tie, backless Marcella waistcoat etc), but I never really wore it for anything other than fancy dress (given the precisely zero times I have been invited to an evening engagement with the Queen, other suitable nobility, or the Opera in the 1950s). These days I'm more comfy in the hot pants (although the tailcoat probably hides the belly better)...