@Bellatrix Wow, congrats on your beautiful new property! What did you end up deciding?
I use the same corner blocks that Bear_with_me shows in their photos of the older beds. I got mine at Home Depot: https://www.homedepot.com/p/Oldcastle-7-5-in-x-7-5-in-x-5-5-in-Tan-Brown-Planter-Wall-Block-16202336/206501693 So easy to install if you are using standard lumber.
@LemonDrop For now, I decided to stick to the set up I used before with the cedar 4x4 as the corner brace with my Trex boards, just to get something in place. I bought a new drill that fits by small hand much better and it was a lot easier putting them together. I reinforced the long sides with rebar, so hopefully they won’t break the nails this time. I will probably change to something else in the future, but for now, I at least have a garden! I may try the blocks on the smaller beds now that I can slow down a bit. I changed to six 4 foot by 24 foot beds (5 are in place now), with a center trellis (concrete reinforcement wire). This will allow me a more easy three-year tomato rotation. I still need to add the regular 4x8 and 4x12 beds, but I ran out of steam. Eventually, I want to do a galvanized roof bed. I ended up with a north/south (ish) orientation, mostly because it looked better with the property.
I left the grass between the beds and they are wide enough to fit the mower through. I’m have a paver patio installed by the house, so it is a bit messy around the garden right now! But these are the first beds, topped with compost. The trellis part still need to be installed. The property is a wonder. The previous owner was an amazing gardener and seeing everything she planted come up this Spring was such a gift!
Oh, and I tilled the grass/soil before setting up the beds, tilled in compost, added some cardboard (in some, not in others), and topped with a mixed of topsoil and compost.
I left grass between my raised bed and it was a pain. The weed eater starting chewing the boards.
I’m not 100% sure that I’m going to leave it this way. If I do, I may dig out the grass by the edges and put down clover seed.
The garden has done very, very well this year, especially considering the late start, the weird weather, and the root-bound seedlings. I am happy with the design and love the wide rows. The first picture is taken from almost the same location as the picture in the original post. A bit of a change!
Wow, everything looks so lush and happy - great job! Love the pooch and patio too 
