There are no rules about where to put the crystals. They can surround the design, lay inside the lines, or on top of the lines. Most people try to follow the pattern and lay the crystals on top. It takes many crystals to cover all of the lines so people sometimes lay the crystal where the lines intersect. And if you don't have a design or grid, crystals in a circle work great. Remember what I said before- crystals are very willing to do all kinds of work for you.
Tomorrow- string art.