Tips for Placing strobes:
On the ground: Placing strobes on the ground is much easier. I personally prefer my strobes to be 4' to 6' apart. I have only seen 3' spacing in c9 light strings, if you have any c9 light stings with 3' spacing, you can skip every other socket and simply place a cap or tape up the empty socket. Each socket can be held up vertically by using c9 socket holders.
Now you can easily hang strobes along gutter lines, fence lines by using C9 light string cords.