I LOVE my new cardigan!!! Hanna helped me figure out how to add extra room in the underarms so I would have plenty of room to layer underneath.

Here are her instructions:
First you should make raglan increases acc. to instructions for your size until you have 34 sts for each front, 50 sts for each sleeve, and 68 sts for back. Normally you would proceed with separating body and sleeves.
However, if you only want to add more room to sleeve, you may only increase for the sleeves and do not make any body raglan increases.
Back should be work according to the Tulle St.
I believe it should be worked as:
R 1: k1, yo, k1; rep. from * to m.
R2: p3, slip 1st stitch of these 3 over other 2 sts; rep. from * to m.
R 3: k1, k1, yo, k1; rep. from * to 1 st before m, k1.
R 4: p1, p3, slip 1st stitch of these 3 over other 2 sts; rep. from to 1 st before m, p1.