Tweezer Pro has done a great guide on the different types of tweezers.

TIP TYPE AND SHAPE

Pointed Tweezers

I’m starting with these because they require a cautionary note. Unless you’re someone who is very comfortable with this type of tweezers, you probably shouldn’t use them. The tips on these tweezers are really sharp and to use them safely, a number of things must be just right (i.e., perfect): the light, your vision, and the steadiness of your hand. The best person to approach your face with a sharply pointed object is probably a licensed esthetician. These tweezers can isolate specific hairs; handle a single, or very short hair; or small, fine hairs; or even (perish the thought) an ingrown one…

Straight Tweezers

Curiously, the straight tweezer is fairly under-appreciated. For starters, it’s much more forgiving than pointed tweezers (less likely to pierce or scratch your skin), and it functions as a very good all-around tweezer.  It’s not only great for women who have been tweezing for many years, it’s equally well-suited to a young woman just learning how to use a tweezer. It will help you capture that stray hair (e.g.., around the chin area) and it definitely lends itself to a “search and pluck” technique.  It’s also terrific for plucking several hairs at once—the larger surface of this tip does the trick.

Slanted Tweezers

Here you get the best of all worlds; the precision of a pointed tweezer and the (search and pluck) advantages of a straight one.  Not surprisingly, it’s the most popular tweezer.  You get a pointed tip for pin-point accuracy and you also get the ability – with a slight adjustment to the hand – to use a straight edge. This is the most versatile style; you get real precision as you reach for a specific hair – or for a splinter. You can get quite close to your skin and have no trouble pulling the hair out to its root. Compared to a tip point, with a slant tip you get more speed with just a little less accuracy.

Rounded Tweezers

This is a kinder, gentler tweezer. It may not feel as precise as the point or slant tweezers, but, make no mistake, if you’ve purchased a well-made instrument, this tweezer will grasp the hair and hold it until you pull it out. The rounded edges do mean there are no sharp corners, however, and that makes this tweezer a terrific choice for anyone whose hands are not as steady as they once were or anyone who is less comfortable with an extremely sharp edge. And, it’s a great choice for adolescents (if you know one who’ll listen to you.) 

Combination, Slant/Point Tweezer

Now here is your splinter tweezer. It’s not as pointed at the end as the pointed tweezer, but it is sharp enough to open the skin, and the flat edge lets you grab the splinter and remove it. Perfect.

SIZE

To judge the size tweezer you really need, you’ll want to consider not only the size of your hand, but also the technique you use when you’re tweezing. While it’s true that a petite tweezer may be more comfortable for you if your hands are small, if you like to hold your tweezer with your fingers grasping farther back from the tip, you might actually find the longer tweezer more comfortable.  If you like to work with your fingers really close up to the tip, you might prefer the smaller tweezer, regardless of your hand size. Finally, if you have a bit of trouble gripping things, look for tweezers with a wide handle.

MATERIAL

First quality tweezers are made of stainless steel – it’s durable, and it doesn’t rust. There are plastic tweezers, and they have their place, but it’s probably not in your make-up bag or on your dressing table.  Plastic is great in first aid kits that may be exposed to the elements, in salt-water environments, or for easy disposal when working with contaminated matter.  They are also completely non-magnetic. Keep that in mind the next time you head for the Lab!