In response to the question about nipple shields, I rarely use them except in
cases when I think the breastfeeding will be terminated without using them.

Two days ago I was helping a mom that had very large (quarter-size) nipples.
 With help, we were finally able to get the baby to nurse on her R side.
 However, her L nipple had an odd shape: it protruded at the top, and had a
tag-like extension at the bottom.  This essentially made it even bigger.  She
was coming off the bed in pain when she tried to latch the baby on this side.
 In this case, I elected to give her a thin silicone shield for this side
only, and gave her the potential warnings about decreased milk, watching the
baby's weight gain, etc.  She was encouraged to continue to try to latch the
baby on without the shield as time went on, and as the baby grows.  I'm
hoping that by just using it on the one side, there will be no problem.

By the way, the entire nipple would not fit into the shield, but she was much
more relaxed with baby nursing.  We did discuss the possibility of nursing on
one side, too. Overall, I can't help but think that this was a better choice
- using a nipple shield - than quitting altogether.

Hope this helps!