Modern sidewalks are poured squares or rectangles. Even the longer continuous paths are "scored" or cut to relieve stress to compensate for ground movement and temperature changes as well as contain damage to smaller areas.
If you are including road or grass with your sidewalk, you could lay your base and use something like styrene, card stock or very thin door skin or wood to raise up your sidewalk elevation from the road or grass. This can be covered with spackle, wall compound, modeling paste, or plaster and as it starts to dry a piece of fine sandpaper can be impressed to give it the texture of concrete. Sress lines can be scored with a knife or as it is setting up, a brass shim can be used to "knife" in the slab edges. By gently rocking it back and forth a little it will bevel the edges slightly and once it is painted and given a wash, they will stand out nicely. If you want to paint the sidewalk, you could do the same by using cardstock to make your slabs and then paint it with a textured paint (using fine sand, or baking soda similar to what is used to make rust on armor exhaust) for texture.
If I am doing concrete I usually paint it a light grey, stipple it with a dark grey and stipple it with white over that. This makes a very nice concrete looking finish.
Mike
"Imagination is the dye that colors our lives"
Marcus Aurellius
A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!"
