Summarize the following:
Find out first if you think there may be style requirements where you’re going. If you’re attending a formal restaurant or a gathering for work, appropriate neckwear may be expected. Consider the situation and use your best judgement.  If you want to wear a necktie, consider paisley prints, solid colors, or neckties with checks or stripes.  If you’re wearing a collared shirt without a necktie, make sure your collar is taut. You should starch and iron it and use collar stays. If you don’t want to press it yourself, get it dry cleaned and ask for light or heavy starch. If you’re not wearing a necktie, keep in mind that the more buttons you undo on your collar, more your look presents a casual and even daring vibe. Consider the people you’ll be with and the mood of the gathering. If possible, pair your blazer with a crisp, new, collared shirt in a white shade. Match your jacket with a dark-colored necktie or bowtie. A sleek combination is a black velvet blazer with dark gray or black suit trousers. For a bit more casual of an evening look, swap out the collared shirt with a solid-colored t-shirt, and top it with a formal scarf. You can get velvet smoking jacket blazers in short or long lengths. This is a lightweight, casual look, typically with two to three buttons that close the blazer over your torso. For an extra convenience factor, get a blazer with side and interior pockets.  For a bold, modern look, wear a smoking jacket in an animal print jacquard, with the rest of your outfit a single, dark shade.  Consider a matching velvet bow tie. Consider elegant (not gaudy) cufflinks. Choose a watch, belt and shoes that are as exact of a color match as possible. Match the metal of your watch, if applicable, to the shade of metal in your belt buckle. Consider adding a pocket square.  For instance, if your watch is a brown leather band, your belt and shoes should be brown leather in a matching shade.  Fold your pocket square evenly. Put it in your pocket with 1/4 to 1/2 of an inch showing. Wear shoes that make you feel confident. You may want to wear loafers, whole cut leather, brogue, or another type of shoe. Polish and shine your shoes. Whole-cut or other dress shoes are more formal, whereas loafers are casual. Loafers look good with light-colored suits. Pair your blazer with dress pants or tuxedo pants in the same color – for instance, black. Add a white or colored shirt and consider tucking a handkerchief in your pocket. Look sharp by adding a bow tie to a white, fitted, collared shirt.

Summary:
Decide if you’ll wear a necktie. Make your blazer into an evening look. Wear a smoking jacket. Accessorize. Choose the right shoes. Pick the right bottoms for a tuxedo blazer.