Always match your belt with your shoes. This is a good rule to follow and it keeps things simple. It's best to stay with traditional colors such a black, dark brown or a rich tan. Other colors will be difficult to match, and generally speaking, should be avoided. If you wear sneakers every day that probably means you are wearing jeans in which case I suggest trying a belt made of fabric or something equally as casual, but please avoid dress belts with jeans and sneakers. If you wear suspenders, I am compelled to ask you why, but I digress. Just don't wear a belt and suspenders together, it's one or the other.
Matching Ties and Shirts. For while the solid-colored shirt with a tie of the same (or slightly-off) color was seen everywhere. This is now a somewhat dated look. Try mixing things up a little and experiment with colors. Ties are great way to express yourself, but keeping it tasteful is your best bet. You can't go wrong with diagonal stripes, modern polka-dots, plaids and subtle patterns. Just make sure your tie compliments your shirt, suit, sweater or what ever you will be wearing it with. Novelty ties are best avoided since the novelty is short lived.
Note: Ties should be tied in whatever style most strikes your fancy. You should know that there are many different ways to knot your tie, and different knots say different things. I prefer the Windsor or the four-in-hand, but I do suggest that you explore a little just for kicks. As for clip on ties--just say no.
Pleats vs. Flat-Front. Why so many men have avoided flat-front trousers has always been a mystery to me. Flat-front trousers look better than pleated pants, at least most of the time. Plus pleats make you look less slim. I have heard guys wear pleats because it’s more comfortable or because flat-fronts are more for athletic bodies. Truth is most men can wear a flat-front trouser. If you want more room then buy them a little big and have them brought in at the waist. This can be done at the store where you buy your clothes or by an independent tailor. And lastly, flat-font trousers are much more fashionable. How do you feel about pants with pleats? Take this poll.
Socks. The more official rule on socks is that they should match the color of your pants, though preferably not the exact same shade unless, of course, you are wearing black in which case it's okay. However, I personally like to wear socks with patterns, such as stripes in various colors. But I do try to match my socks with my pants and shoes. To quote Glenn O'Brien from GQ magazine, ". . .you will ultimately realize that beyond the valley of rules rises the mountain of aesthetics, the peak of which (if there is one) is always shrouded in beautiful clouds of various hues, many of them resembling certain of my more unusually hued socks."
Note: Although it should be obvious, white socks should be reserved for the gym.
Watches are the single most important accessory a man can own. I really suggest investing in one good watch that suits your lifestyle and taste. However, if you are someone who likes to own more than one watch, wear the appropriate timepiece for your outfit: black band with black shoes and belt; brown band with brown shoes and belt; and silver band for either. See my Men's Watch Guide for more in depth advice.
Eyeglasses are one of the few ways you can really express yourself. I have worn glasses for many years and I love having a few pair in different styles. They don't have to just serve a function, but can enhance your overall look. Do your best to find a pair of glasses that not only compliments the shape of your face, but also expresses your personality. Ask people who wear glasses for a place where you can get good advice about what shape and style looks best for your face shape and features.