Several years ago I had used some cross ties to construct planters next to the house. It seemed like a good idea at the time. I knew they would eventually rot, but everyone told me that they would last a "long time". In my case, some started looking bad in about 12 years, and all of them had some rotten spots on them in 15 years. After 16 years even I had to admit that they had become an eyesore and had to deal with them:
   

The first thing my wife and I did was come up with a unified landscape plan for the area around the house. In addition to the rotting cross ties, we needed to replace the plants. Some of them had started dying in the spring. The plants had looked good individually, but they had grown too large for the area and had conflicting requirements for water/sun/soil. We decided to rip everything out and start from scratch. We spent a couple of days talking to plant nursery workers, researching various plants on the Internet, and walking around home supply stores. I was anxious to get started, but I feel this plan saved me lots of time and money in the long run.

Finally a plan we both could live with was done and I started ripping out old plants and cross ties. The shrubs got yanked out by a chain attached to my truck, but the cross ties had to be dug out by hand. I put in some blocks on level ground to the right of our front door, and that was easy. All I had to do was compact and level the ground where the cross tie had been (I did not use a sand base layer since our soil is very sandy). Then I placed the first row of block, being careful to keep the block flat, level to the block adjacent to it, and butted up against the driveway or walkway. Because I had chosen interlocking blocks, stacking additional blocks on top of the base row was very simple and no skill was required.

Then I started work on the side of the house where the land sloped to the back yard. I had to start at the bottom, in the back of the house and work my way to the front. It was not hard, but neither was it rewarding since it looked like nothing was happening when viewed from the front.

The block we had chosen was cast in the shape of an isosceles trapezoid. The long edge was the front face of the block and it was rough cast, but the sides and back were smooth. This made it easy to have the block follow the bend of the walkway. The block at each corner had to be cut by hand in order to keep the look of the block consistent. It turns out that cutting the block by hand was not hard. Click here for a short write up about how we did this.

When I started laying the block, it took me 10 minutes a block to get it positioned properly in the x, y, and z axis. By the time I finished, it was under 3 minutes a block. Since the blocks needed to be level and straight, I used a laser level to keep thm in line with each other, and a torpedo level to keep them horizontal. I used a string tied to a rod driven into the ground as a center point when I needed to set the blocks in a radius.

I still need to finish leveling the dirt. We will plant new plants and add the ground cover, this spring. Here are a few pictures of the finished block wall:
       
The base layer for all rows is buried and not visible. On level ground I tried to have no more than 1/2 of a block exposed for row #2, but sometimes I would bury row #2 also. If the ground was inclined, I would bury at least 4 blocks beyond what was exposed by the slope of the land.

For the wall on the LH side and LH front of the house I used approximately 400 blocks. I had not estimated an amount, but this is more than I was expecting.