It astounds me how many men I see with gaps between their wrists and their dress shirt cuffs that you could drive a truck through. Your cuffs should be snug, but not tight enough to be uncomfortable. You shouldn't even be able to insert one finger into your other arm's cuff once it's buttoned. If you find that too tight, I suppose it can be loose enough to insert one finger -- but never loose enough to insert two. Loose cuffs look sloppy; snug ones not only look neat, but also make your watch easier to see by preventing it from slipping under your cuff. (You could also wear your watch over your cuff, like some great dressers have done. But it looks affected, and if you're sure enough of your stylishness not to care, then you probably don't need the advice on this blog anyway.)
Dress shirt sleeves come in two types of sizes: exact, i.e. 33, and combined, i.e. 32/33. Combined sizes allow manufacturers to save money, and these are generally done with cheaper shirts. Combined sleeves have two buttons on the cuff, rather than just one on the end. I actually prefer combined sleeves because I have small wrists, and the inside button makes my cuff snug without my having to take a new, exact size shirt to my tailor to have the buttons moved in. But then I also tend to wear a 35 sleeve. Even so, for those who wear the lower measurement of a combined size, I fail to see how an extra inch distributed across the entire length of a sleeve is any great concern.
What especially astounds me is how many men I see with sloppy cuffs with two buttons visible -- which announces to the world that you wear cheaper shirts, looks especially sloppy because of the extra visible button, and means that you didn't even have to take the shirt to a tailor to make it fit (or move the button yourself, if you know how to do that); the extra buttons to make their cuffs fit properly are already there, and they're not even using them! For the life of me, I cannot fathom what is going through a man's head to wear sloppy cuffs -- especially when he sees that he already has another button to make them snug, yet he chooses the outside button.
This is exactly what you should never do:
Unless you have big wrists, use the inside button if it's there; if it's not, spend the couple of bucks to have the buttons moved in -- or move them yourself. And, if you do have big wrists, have the inside buttons removed -- and save them, in case you need them for replacements. Wear snug cuffs.