Question about sizing (NEWB)

It seems every time I think about how big I want my final image to be sizing questions arise. Specifically screens, squeegees, and scoopers. I was just wondering if anyone had tips on this. Do you make your own screens/squeegees, and how do you scoop your emulsion? I have a variety of different sizes and none seem to line up well, meaning the squeegee is either too big or too small for the screen. Also, if the image exceeds the biggest screen you have, you would divide it in half and line it up later on two different screens, correct? Any help would be appreciated. I got a deadline, and i've almost started.