I realize this should be an easy thing to do, but I want to be certain before I have to tear out yet another project...I am knitting the easy mittens in the One Skein Wonder book. The directions are for only 1 mitten; i.e. there is no right or left. However, this mitten feels very strange on my left hand. Could anyone tell me how to make a left mitten? I have 3 DP needles with 12 stitches each. The right mitten thumb gusset is started after the first 2 stitches on the first DP needle. I know somewhere in the middle, I should start the left thumb gusset, but I am not certain where.