When Blair is in bed...

She's in bed asleep/going to sleep in:
1x04, the very beginning when she wakes up from a dream about Serena.
1x04, about halfway through when Eleanor tucks her in.
1x04, about 5 minutes after the scene mentioned above, she wakes up ready for her modelling job.
1x14, at the beginning when she wakes up from the nightmare about her/Nate her first day back at school after she was humiliated :'o(
1x18, at the beginning when she wakes up next to Chuck.
2x08, at the beginning when she has her little dream about Chuck.

That's it for when she's been asleep/going to sleep, but she's also on her bed:
1x02, near the end laying with Nate.
1x10, near the beginning when she and Chuck are being adorable.
1x11, near the end when her daddy comes and tells her she still means everything to him (I love Harold!)
2x21, near the end when she's upset and talking to Serena.

I believe that's all of them...

I hope your video goes well, make sure to link it when it's done, I'd love to see it!