When I got my first screen printing kit at Michaels, it came with a small squeegee. This is what I used to apply the photo emulsion to the screen. Using the squeegee was awkward to say the least. The first times I used it, it did a poor job. I got slightly better using it, but it tended to coat the screen thicker at some spots that others. It would push the photo emulsion through the screen. So the coating would be uneven in thickness. So when exposing the screen, parts of the screen would be exposed before other parts of the screen. I read about a device called a scoop coater (also called an emulsion coater). It isn’t anything fancy. It’s basically an aluminum trough. I ordered one. The instructions I got were sparse. It took a bit of playing, but the scoop coater does a great job of applying a thin even coat of photo emulsion to the screen. An even coat is important! A thin and even coat will give you better detail, and sharper edges on your final results. And the scoop coater just makes the whole job of coating the screen with photo emulsion so much easier.
When buying a scoop coater, keep in mind the size of screen you are going to be using. If you buy too big of scoop coater, it won’t fit inside the frame. And if you buy one that is too small, you will have to make multiple passes. Still doable, but not as clean of coating as a single pass.
I got my scoop coater at Dick Blick, and have been very happy with it. If you going to do more than one or two small projects, you really should invest in a scoop coater as it will make your life easier, and your screen printed t shirts better!