Chest-type deep freezers are arguably more efficient than uprights, but a lot of people avoid them because they don't like having to dig for things that make their way to the bottom.
I keep ours organized by using plastic bins. I buy these at Dollar General or Big Lots for $2 to $4 each. I think they are the "sweater box" size. I don't use lids on all of them, but I do keep the lids around in case I need them.
Each container has one kind of food in it. One for beef; one for pork; one for processed meats like bacon, sausage and hot dogs; one or two for chicken; several for venison. Right now, most of our veggies are in the freezer of our spare fridge, but if they are in the deep freeze, they get their own container, too. Any overflow goes into the side baskets.
Organized this way, I just lift out the containers to get to what I need, which somehow is invariably at the bottom. I don't have to dig, I just have to move a couple of totes out of the way.
I use similar totes in the across-the-top freezer on our main fridge in the kitchen. These totes hold all those already-opened, partially-used bags of veggies, fries, etc.
Now, I wish I could figure out a better way to organize the freezer side of our side-by-side spare fridge in the garage. This upright freezer layout is new to me and I just haven't got the hang of it yet. I just throw things into the pull out baskets, but things just don't seem to stay very well organized in here.