I stuck with the arrangement motto that you need a "thriller, filler and a spiller".
Pick a well draining bowl or container.
Fill it with cactus mix soil.
Then start adding the plants.
I started by already having a plan laid out in mind. I like to use the tallest plant in the center for my "thriller", then do my "fillers" opposite each other based on color and leaf shape. Then I went back with the "spillers" and put them on the outer edge so they would grow out and hang down.
Then I went back and added a few pebbles to provide extra support and cover any bare spots.