Having the correct presser plate, sometimes called a throat plate, can make a difference in how your doll clothes turn out. There are two main types available.
A universal throat plate usually comes with your sewing machine. It has a wide hole where the needle goes through that allows you to do all sorts of straight, zig-zag, and fancy stitches. It is suitable for most sewing jobs on your machine.
The other main throat plate available is a straight-stitch plate. This type of plate is used for fine fabrics where there is the danger of the fabric being "sucked" down the needle hole and jamming the machine. I also use this type of plate when quilting--there's less trouble with jamming and you get very precise seams--just what you'll need for doll clothes!
Here's a comparison of my two throat plates. The one on the left, which is installed in my machine, is the straight stitch plate. On the right, I've laid the universal plate, which is used for all sorts of stitches.
You can see how they differ--the universal plate has a wide hole for the needle, and the straight-stitch plate just has a little round hole.
It's easy to change your throat plate. I mostly use the straight-stitch plate for doll clothes, and then pop the universal in for zig-zagging or fancy stitches.
Other Presser Plates
There are other plates that are rarely used available, usually by special order. The other plate I have seen is one used for eyelets. It has a special attachment on it for fixing an eyelet tool, which will allow you to feed the work through the machine in a circle and make an eyelet using a button hole stitch.