Dry stone walling is an ancient craft that can take years of practice to do rapidly and proficiently. A professional dry stone waller will build a wall with amazing speed, hardly pausing to decide on which stone to use next. For the rest of us there is more trial and error involved, and if you are doing it for pleasure it doesn’t matter if it takes a little longer to select and position the best stones. Provide you take your time and aren’t over ambitious, you should be able to produce an attractive and stable wall. No two stones are the same, so don’t worry if you find it difficult to find stones that have to look similar. Different kinds of stone have different appearances: sandstones may be large and chunky; slates usually come in flatter sections. Be prepared to work with whatever local stone is available economically. Remember that building a dry stone wall is not a job for a weekend. Think of it as a project to spread over weeks or even months. If you don’t rush it you will probably make a better job of it and probably find it more satisfying.