You're getting a lot of silly answers, because it's a silly question. Every woman is different. But I have gathered a bit of data that might answer your question, somewhat.
Skin. Old gals have old skin. I'm a touchy feely guy, so this is important to me. To better understand this, shake an older ladies hands and really pay attention to how the back of their hand feels. It's going to feel the same everywhere else.
Scent. Not gross, relax, but older gals like to doll up, and sometimes it's overwhelming. Lotions, perfume, Ben Gay, talcs, hairspray, you get the idea.
Moisture. Really older dames sometimes have a difficult time getting the fluids going. So, lubrication is helpful.
Hair. Most older gals DGAF. So if you're into the shaved parts things, that's something to consider. I've never come across a really unattended garden, but the perfectly manicured lawn is a seldom sight for the 50+'ers.
Energy. This really depends on the lady. You can get a good sense of an active lifestyle lady just by checking her out. I once had the pleasure of knowing a retired womens tennis pro. That was exhausting awesomeness.
Affection. Older are just younger ladies in older chicks bodies. I mean that, even a 20 year older than you gal still loves a cuddle, a snuggle, a long embrace. They are more receptive to acts of chivalry and straight 'good guyism'. I've found they reciprocate kindness, and have more willingness to please.
Kissing. I really believe there is no wrong or gross kissing, only compatible kissing. Older gals don't French it up much. Pressing of the lips for awkwardly long moments happens often. Must be a generational thing.
Sex. Well it's sex. Most gals respect the fact that it's just that. Once in a while you'll get a gal that gets a little clingy. Usually, the one in denial about her age and reality of the relationship. But for the most part, they don't call often. They don't text often. They don't nag or have fits of jealousy. It's quite nice.
Gifts. They give gifts. Everything from money to a home cooked meal. It helps if you're sweet and never demeaning or condescending. They will insecurely bring up their age often and say things like 'I could be be your grandmother!', you say, that's nonsense and compliment them on anything.
The older we all get, the more we want to be young again, feel young, feel anything. Remember that and tread lightly.