Two importent things.

First take lots of before, digging, and after pics. You will regret not taking pics. Second have fun. I will not take long to dig, if you are having fun with freind or family members helping. I have a shelf on the sides for potted plants. You can use a hose pipe to out line the shape and when you have the shape you want use white paint or flour. I also used a garden tiler when the ground was too hard to dig.