I recently redesigned a 4X4 foot 16 inch high pallet wood raised bed and it was very easy to build. I get my pallets for free, so it's the first thing I try to use when I make projects out of wood. Anyways, here is a picture of my latest pallet wood raised bed, total cost less than $1.00 for screws and brad nails. If you are interested in something like that, you can find that build and other designs on the thread
Show Me Your Pallet Projects!
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Depending on your age and physical limitations, raised beds are just so much easier to maintain. At 16 inches high, I don't have to bend over very much for any work. A couple of weeks ago I met a couple older than me and they were going to use full pallets at 43 inches high because the wife had hip surgery and could not bend over at all.
At least with free pallet wood, you don't break the bank in setting up a garden. The plants don't care how much you spend on the project. So, just decided what you need at this stage of life and make a garden bed that works for you.
FYI, I use the hügelkultur method of using wood tree trunks and branches on the base of the raised bed to fill up space before I add my top layer of compost and topsoil for planting. I have to buy my topsoil, so it saves me a lot of money using all that wood tree trunks, plus the hügelkultur method acts like a giant sponge to store water.

I reached an age where it was just so much more enjoyable to work in raised bed gardens than in ground planting. All my new gardens are raised beds. I don't look back.