Although I have yet to get around to building it (3 years and counting) my fencing plan was basically the #3 design described on that webpage. Putting in 8 foot tall woven wire would probably be better, but 4 or 5 foot woven wire is readily available from big box stores and craigslist so the cost can be a fraction of the 8 foot stuff.
In addition to protecting against deer, you will also need to protect against rabbits December through March. My experience has been that a good trapping regiment coupled with trunk barriers will take care of almost all the rabbit issues.
This solution isn't a fence but it does solve the problem of bark nibbling/girdling by rabbits and rodents. I first thought of this when I discovered that several trees in my orchard had been completely girdled. I tried tree wrap fabric and the rabbits went right through it. Commercial tree tubes were too expensive...
So I bought 200 feet of black corrugated 3" drain pipe. I laid the whole roll out on the driveway and used a jigsaw to cut a slit along the length of the whole 200 feet. I then used a sharp utility knife to cut the pipe into 18" sections. I simply eased each 18" section of pipe around the trunk of a tree and it definitely did the trick. In four or five years the tree will outgrow the pipe and you simply remove and reuse. Cheap and easy if you're dealing with rabbits. Deer... I don't have to deal with.
Deer are a major problem around here and the only one-stop permanent solution is deer fencing or dogs. Obviously the right kind of dogs. I once reasoned that the fencing would be cheaper than the dogs, but I've found that over time that's likely not true.
Deer fencing has to be high -- 7', and secured on the bottom. It's expensive and you need lots of T-posts to put it up. It's going to be an effort and it will cost, but once it's up and done right it will exclude them 100%
A single 330' roll of heavy weight deer fence is $300. 10' T-posts are $7-8 each if you buy in bulk. This might be worth it to you, and if you fence a larger area you can fence a garden area as well. Around here people simply don't have gardens without it. I can give you lots of time and money saving advice about how to put up deer fencing but I would consider your costs before going that route.
Deer are browsers and they love young tender tree branches. My mature trees I've got so for the most part everything is above deer head height. They will still nibble occasionally but they won't stand up to reach higher branches when just browsing unless they are desperate. For the younger trees I have to use fence. They have done so much damage that it set that orchard back years and some trees will never be the same.
I would probably try getting poly deer fencing and making individual "cages" for each tree. Just cut a section long enough to create a circle big enough to enclose the tree. Because they are browsing it doesn't have to be that secure. They won't push under and can't jump over if the diameter is less than a body length or so. A circle of fence maybe 8' in diameter should serve you several years as the trees mature, depending of course on the tree. In this situation they will just see the fenced tree as an obstacle and ignore it.
To secure the circle of fence I'd think two 10' T-posts on opposite sides will be enough if you get the thicker fencing, which is relatively rigid and stands up on it's own. Of course poly fencing isn't the only option, especially if your trees are still very short. But this way you won't have to change anything for along time.
The poly deer fencing I recommend is Tenax C-flex or C-flex P but in this case you can go with the lighter weight stuff (and maybe only 6' ) because you aren't worried about a deer being able to break it. Once in a while if a deer is panicked it will try to get over my fencing but because I have the C-Flex P they usually just bounce off. You can get very cheap deer fencing just about anywhere and that may be appropriate in your case, but for me I find that the cheap stuff doesn't last. With Tenax you can get 15 years out of it and thus re-purpose it after the trees are grown.
I have had a very successful 8 foot chicken wire fence for 10 years.
The pole tops are at 8 1/2 or 9 feet. The poles are 10 feet apart. Occasionally a really bad wind storm has made the poles lean outward, so I've added a couple more. They are the metal fence posts that go in with a pounder.
I run a neon green poly construction string around the very top, from pole to pole. That warns the birds that don't quite see it, but it also gets the fence up slightly higher without having extra fencing material. That string lasts at least 4 years where I am, and I can see it at a distance, so if any part of it breaks, I can spot it without having to walk the total circumference.
I ran one 4-foot chicken wire roll horizontally around the poles as the first bottom layer, bending it outward 6 inches at the bottom tight to the ground, so rabbits cannot get under it. I use galvanized wire to tie it to the poles.
Then the next horizontal level up is a 3 foot roll of chicken wire, which gets it up to 6-1/2 feet, and the string becomes the 8 or 9 foot level. If your top wall of your fence is uphill, make sure the string is extra high, as they will be able to stand higher and jump over more easily, so that's where the 9 foot string height helps. I ran a galvanized wire sort of "sewing" the edges where the two horizontal rolls meet, because the deer can learn to push through if they see an opening.
If you can spring for the fully galvanized wire, it will last for years and years. I had some construction chicken wire rust out, and the deer learned to push through the rusted parts. But it's not hard to replace it, if you need to start with the economy wire. I have found the construction wire, 200 foot roll for about $50.
Our livestock are deer. We feed them. We have 4 food plots that we keep them off until the plants reach a certain height. We use two things for temporary fencing. Electric fence and scent tape. You need two fences about 3 ft apart. deer will jump the 1st fence but not the second.
You will need something permanent. Deer can jump an 8 ft fence if they want to. Axis deer will go under a barb wire fence.
I imagine that this is dependent on the type of deer that you have. I have a 4' chicken wire fence around my orchard that has kept the deer away. I intend to reinforce this with a junkpole / plastic string fence that will be slightly taller.
Rabbits are a year round problem for me. Each of my trees has a mesh around the lower part to help keep the rabbits off. The rabbits did dig up a few of the trees when they were newly planted.
I still have a lot of work that needs doing on the fence but for now it is enough. Just need to ensure that it effects continued protection.
I have had good luck with baited electric fence, both for deer and other critters. The principle is the same for all. Hang a single wire at nose height of the desired critter, preferably out in the open. Put little tags of aluminum foil every few feet along this, with a swatch of peanut butter on each one facing outward. Critter smells this and gives it a lick or a nibble and gets a really good shock! Critter is not back for months, and tells all his friends too! I have used this same technique to keep goats in a single-wire perimeter as well. You need a good fence charger and damp soil.