These are some of my ponds. The larger one I made like this: firstly I dug out a big hole and flattened it at the bottom, removing any sharp stones and roots, then made the sides vertical and hard all round, then I put an inner liner in it, an old duvet or a rug or some more plastic. Next I put the actual pvc liner in the base and up the sides to overlap, then shovelled in (carefully) some soil that I had dug out from the hole, taking care there`s no glass or sharp bits in, then started to stack up rocks and bricks all around the edges inside the pond for the walls. You have to make sure no sharp edges scratch the liner so I use double lining all around the rocks part, cut offs is good. After all that you plant up the water plants and oxygenators into the soil and fill with water. The rocks will hide any change of levels so that isn`t so important, and infill all around with soil into pockets between the outer top rocks or paving stones to give a natural look and drape them over into…