Hi Jonathan,
Seeing as you are fairly new to catsailing, you might have fun with this little drill. To begin with, try this on a "light air" day so that you have time to let things sink in. Lock your rudders in the up position and put the helm down. You can do this by yourself, or better yet, get the crew involved. Ease the jib "a little" and tighten the main "a little", ease the main "a little" and tighten the jib "a little". Tighten the main and jib together, ease the jib and main together. Let the jib "fly" and tighten the main. Let the main "fly" and tighten the jib. Once you get a feel for what this does to steering your boat, go through as many variations as you can come up with. Lesson #2...Go through the above routine with as many variations as you can come up with regarding crew weight distribution. Both at the stern, both at the forward beam, one fore and one aft. Once you learn how to "steer" your boat with the sails and "weight distribution" you will realize that the rudders are there to "guide" the boat. Hope you have fun, and it will save your rudders and castings.
Dave