Before laying out the pattern, you'll want to see if the knit ravels by stretching both crosswise edges of your fabric. Very often runs occur more on one edge than the other, so take a mental note if you see that because you'll want to use the more ravelly edge for your hem edge since we always mess less with the hem area we're sewing a project.
Once you've lain your fabric down on your work surface and have begun to arrange it all neat, check that the fabric is sitting entirely on the work surface with no hanging edges. That overhang will distort your knit fabric, pulling it off-grain and resulting in one misshapen pattern piece. We no likely.
If your knits are slippery, patterned or bulky, it's best to cut through only a single layer of fabric at a time. Sure, it takes a little longer but the straighter cutting will be worth it. The other thing you'll want to do is to place a couple weights on the pattern/fabric to keep it stationary. Actual sewing weights are nifty, but whatever you have around the house will work, too. Alternatively, you can place a piece of cardboard below your fabric, then stick pins through all the layers (pattern, fabric, cardboard) to keep it down.
When you're ready to mark the fabric, use water-soluble marking pens, pins or chalk. If you're lazy like me though, you can notch it with sewing scissors (tiny notches, of course) but only if the knit fabric you're working with is not a raveling (unraveling?) kind. Otherwise, say goodbye to your seam allowance in no time.
By Emily Parker