Here's another thing I have found that's helpful (and often forgotten), change the sewing machine needle fairly often. While it's true that the machine will still push through the many layers, its better for the machine and the material if your machine's needle is sharp. They're cheap enough and come in a variety of types. If you're sewing canvas, look for a sturdy needle (like for sewing denim). Have fun and you'll love your first kilt (even if its not perfect).