Breast pads in bed...

i used cloth BP and they were good. I think maybe because it's fabric on fabric and not plastic backing on fabric it helps them grip to your clothes a bit more? itms...

I leaked alot in bed and it was awful being in cold, wet bm so I would recommend using pads or something else absorbent

I have big BB's (like E-F cup at the moment) and they kept falling out the sides of my maternity singlets and maternity bra's, so I now wear a sports bra and it does the job of keeping the pads in place (prior I was always waking up with wet sheets and doona lol I leak so much the breast pads are always over full and splitting apart when I wake up in the morning).
Probably helps that I'm only expressing though as getting DD on latch on on a regular basis is a battle.

Just thought to add, I would use baby bibs they arent quite so bulky as flannels but still do the job- most of the time :) But also if it's really annoying you you could try lilly pads. I have not personally tried them but know women who have and they seem pretty good.