I'd add a few more things. Make sure your shirt and jacket fit. The most common things I see are men with collars too big for them so there's this huge gap betw

I'd add a few more things. Make sure your shirt and jacket fit. The most common things I see are men with collars too big for them so there's this huge gap between the front of the neck and the knot of the tie. Make sure your shirt fits snug, along with the suit jacket. The suit jacket should follow the contour of your sides, not hang straight down. It should look tailor-made for your body shape, and those with jackets that drop straight down on the sides look as if they purchased a one-size-fits-all suit. Also, ties should reach mid-buckle, and the knot should be appropriate for the occasion. I see lots of guys at weddings who tie their knot using the simplest method and it looks too casual. Look up various tie knots like the half-windsor, etc. And as he said, your pants should reach the floor, but they should also drape nicely around your shoes. I see lots of guys with bulky dress shoes that cause scrunching of the pant leg at the ankle because there's not enough room for the pants to fit over the shoe and drape; so pick slim fitting shoes. I disagree with him on the shinier the shoe the dressier and that they should be made of leather. I've got slip-on black suede shoes that work really well when dressing up.