Treats!

Horse treats. I have used the Purina Apple and Oat, Nicker Makers and Senior Berry. They are all around $15 for 15 lb bag and the deer like them all. The Apple and Oat are the largest biscuits, and the Berry are smallest. Berry are also nice to put in your pocket as they sluff off less powder when you handle them.

Manna Pro has two apple treats that are essentially the same thing, just a different shape. Saddle snacks are like a large piece of chalk. Apple Wafers is like two of those chalk pieces stuck together side by side. You get less fragments in the Apple Wafers. They also have a Peppermint Wafer that is the same shape. The Manna treats really should be called "bricks" instead of "Wafers" as they are very, very dense.

The Manna treats are cheapest, but the deer like the Purina better.

But their favorite treat by far is soft corn tortilla. You can get a stack of 80 for about $2.50 and they keep for a week or two without spoiling. You can also throw them like a frisbee to deliver them to specific deer.

My deer and elk love carrots, parsnips, apples, the horse apple treats both by purina and sprout. My elk will eat pears & celery but my deer wont touch either of them. I smear peanut butter on trees in the pens. They love licking that gone. I've done peanuts & sunflower seeds. However what goes over like its the best in the world and even preferred over corn is raw soybeans. They absolutely LOVE soybeans. My elk enjoyed it in early summer but for the most part ignore it and love the corn more. I don't do much corn in general trying to avoid gut problems from it.
But if you can get from a farmer after harvest and bag the soybeans they will stomp over each other for it.
I toss scoops out, I don't normally leave in piles. I find they like to "graze" for it and that way no one can lord over a pile and they have to look for it like they would have to look for food if they were wild.
Fresh greens, branches with leaves in late spring and over the summer I do for them since in winter its not possible to do that up here.
Watermelon in the summer, pumpkins & squash in the fall.