I like to pack lots of layers - I will pack leggings so I can put them under jeans or a skirt. I pack those teeeny stretchy gloves, a headband-earcover and a scarf. It gets expensive to buy that stuff at WDW.
We use a backpack so we can store them as we take things off or put them back on ...
Watch out for days when the wind is coming out of the North, even if the temp is in the 60s, the north breeze makes it feel cooler especially waiting at Epcot for Illuminations.
In winter I always pack a small flashlight, sometimes paths can be dark, I also have used it to make shadow animals to amuse myself and kids around me while waiting in lines.
One of the things I have noticed about myself: I do better if I am IN the park as it gets dark rather than getting myself motivated to GO to a park after dark... I think I just like to go back to my "cave" at dark and stay ... and if it's dark AND raining, I get so depressed that there better be a place to eat in the hotel ... last trip we blew off our last night at the Studios because it was cold and rainy ...