For multiple cats...

[Momto4FemaleFelines]

I pretty much know who is who by how they jump up or how they feel as they jump up.
Kit will usually trill when she jumps up.
Piper is the heaviest of the 3 who gets in bed with me usually before I fall asleep.
Molly doesn't usually come until the middle of the night and I wake up with her ON me somewhere. But if she jumps up when I'm awake, I know it's her as she'll also trill but in a different tone than her sister, Kit.
I also know who is who by the position they settle in.
Kit will snuggle up next to my side if I read for awhile, but moves to the foot of the bed when I shut the light off.
Piper will lay on my legs pelvic level for some pets before moving to the foot of the bed, where Kit sometimes will give a big hiss at her warning her not to snuggle if she isn't in the mood.
I also know who is who of these three by feeling them. All three have a different texture too their fur.
My fourth girl, Philly, prefers to sleep alone downstairs.

[Freedom]

Most of them I can identify. In fact, when I can't tell who it is, I completely wake up!

[aTailOf2Kitties]

Toby is heavier and usually jumps on my upper half. Havoc usually jumps up towards my feet. If I happen to almost see the cats in the dark I can tell the difference because Toby has a wider head and his ears are more rounded and farther apart. If that fails all I have to do is touch them. Toby's fur is a whole lot thicker and softer than Havoc's.

[phesina]

Elmer flings himself up into the air and lands on me and the bed wherever.. Sparkler drags herself up the side of the bed with her front paws and spills over onto the top.. Poppy jumps up gently and settles herself either on my tummy or else on the pillow just past the top of my head so she can groom my "fur"... Sydney jumps up and settles down near my hands and face so he can easily arouse me when it's time for me to serve their breakfast (any time from 1:30am on)..

Bob is the only one who doesn't jump up on the bed.. He just wobbles up to me when I'm sitting on the couch or here at the computer, so I can pick him up and hold him on my lap.

[katladyd]

Ming, in all his 20 lb. glory, jumps on the bed and literally causes it to vibrate. He will always sleep by my feet or across my legs. Mac jumps up by my feet and immediately makes his way to my chest and sprawls across me, purring, while he gets his pets. Sometimes he love to make biscuits while he's up there. If Mac is somewhere else, Ming will cautiously make his way up my legs and tap my face with his paw and murp, as only a Siamese can, get a couple pets, and return to my feet.

[Catlady711]

If Bear jumps on the bed you can't mistake 17lbs of cat landing. lol

Hard to tell with Sassy & Sabrina, they both weigh similar, however Sabrina usually goes right for hubby's side while Sassy heads for my nightstand, turns around, then lays by my knees and pins me in the covers, if she's cold she heads for under the covers on my side. The whole time Sassy is doing what I call her 'squeaky purr'.

Jack rarely jumps on the bed when there are people in it.

Pooky makes a 'maaarrrooow' whine if he's heading to my pillow wanting under the covers, otherwise he settles down on my feet where he jumped up at.

Cami used to sneak in after I was asleep and settle down between my knees, now that she's relegated to live in a separate room, I really miss her doing that.

Josh has a whole routine when he goes to bed. First he races to get to my pillow before I even get in the room. He dances around on my pillow for a bit until hubby gets settled, then goes under the covers on his side. Once I get in bed he gets out, walks across the pillows, pushes his feet in my hair (which usually hurts), sticks his cold nose and tickling whiskers in my face and purrs very loudly in my ear. He tries to nose his way under the covers and if no one is already there I'll let him under and he goes in and lays down with his fluffy tail in my face. After about 10 minutes when hubby and I are just starting to go to sleep, Josh will get out, walk across the pillows, flipping his tail in both our faces, and proceed to get back under the covers on hubby's side. It's quite the routine and we go through this every night!

I can identify all the cats at night, in the dark by feel, and some (Sassy, Josh, Pooky) by their purring.