First I dug out the existing soil and added sand. Before adding the sand I lay newspapers at the bottom.
Then I placed the rocks I had prepared last week on the bed. After that I placed the potted plants on the bed to visualize how the bed would look like once planted.
Finally, I used the gravels to decorate the surface. This is the final look of my bed. Thanks to the inputs from GW.
I really like the look of it. The plants I used in the bed had been put outside in the rain for several months to 'harden of'. Now, let's see how they would behave.