Instructions for incorporating plants in your stonewall are at the end of this article. A slight backward angle makes a world of difference to the sturdiness of your wall. Remember to always set the cornerstone and work backwards when you get a few feet from the end of a course. Fit stones together as well as possible. Use wedge stones to stabilize larger stones or to fill in small gaps.
Small joints are the key to a nicer wall.
Be sure to stagger your joints. You may ignore this rule occasionally if two stone happen to fit together particularly well. But never do so for more than one course. Vertical running joints can cause a weak spot in the wall. This will help you to see what you have to work with and find the best fit.