Waist: a rookie mistakes, especially in the times of tighter-is-better, is that your waist should be as tight as possible. Wrong. Even for the thinest of men all that will do is make you feel uncomfortable, and probably give you gas. Even worse, when you unbutton your jacket your waist will look funny. . Just make sure that the waistline is comfortable and that you can always stick two fingers into the waist while you're wearing them.
Pleats: its totally up to you. But if you have on a very classsic color like grey or navy, they always look good. For lighten blues and pin-stripes you may want to go for a younger look and leave the pleats to the old men in gray or navy. However, if you are fat, they may help you hide your gut. And vise versa for very thin men.
Cuffs: the extra fabric helps the pant hang off of the leg nicely properly by providing a little weight at the bottom, which adds to the break over your shoes. They look better on someone with long legs, so if you are under 5'5" dont try this. Standard 1.25" cuff is always good. Unles you are wearing Thom Browne, then go as high as your heart desires.
Accessories: Your belt must match your shoes, and leather is the preferred material. Your shoes should also be leather. As for color, you usually can't go wrong with black. Your socks should match your pants, or your pocket square if you are more savvy then the average beginner. No thick black tube socks PLEASE!!!
If you are a man and you don't know any of this, I will be taking accepting cash only to come and help you out PERSONALLY!! I require a three hundred dollar deposite and I will decide how much I'll charge you depending on your attitude.