For multiple cats...

[Taz_Zoee]

When I had multiple cats () I could tell simply because Taz was much bigger than Paizly, or Taz would growl at Paizly. But then toward the end he actually weighed a little less than her. But he (Taz) would come up right to my face to settle in. And she (Paizly) will sleep in the curve of my stomach when I'm on my side.

I can sometimes tell the dogs apart when they jump up too. Mostly because when Taggart gets on the bed he immediately flops his head down and Zoee will either sit with her head up for a while or gently lay her head on her paws. I can also tell the dogs by the feel of their coats. Zoee's is much thicker than Tagg's.

[Gin]

Yes, I can tell. Sasquatch is the large lump reclining beside my knees. Missy is either sleeping on my pillow or kneading my upper arm and purring loudly in my ear. Striker is curled up with Sasquatch, unless it's time to get up and eat breakfast, in which case he's knocking things off my nightstand and patting my face.

[Kalei]

lol, some people...cats all have different personalities and ways about them so why wouldn't someone know them by how they jump on the bed?

When I had my Bobo, I could tell if it was Bobo or Kalypso jumping up on my bed.

[dehlers43]

It's easy to tell the difference between my two - Franklin weighs about twice as much as Chelsea.....
When in bed I can also tell what kind of mood they are in without actually seeing them. Chelsea will gradually tense up before she whacks at Franklin (sometimes a momcat need some alone time!) and Franklin has a certain "feel" when he is about to drop some toy on my chest, wanting to play.
Nothing special - just the stuff any cat person knows about their purrkids...