Here is one way but I haven't tried it.

http://nsrca.us/index.php/d5-news/94...90-fieldlayout

This way is easy to do but hard to explain.

I use a long piece of heavy string with three cheap screw drivers also, large nails would work. Usually, we buy the parking lot paint to draw the lines. The little cart they sell does make it easier but frequently only fits one brand of paint. Buy the whole box because it takes way more than you think especially if you are going to set up for two flight lines. On grass white is generally more visible than yellow.

Tie a nail at each end of a string about 50 feet long. Hold the two nails and stretch it out to find the middle and tie the third nail leaving you with two equal lengths between the three nails. Paint a line parallel to the flight line about six feet long as the base of your pilot station. Then stick the middle nail in the middle of that line for your center line. Extend your string out perpendicular to the base and place the in the end nail and paint your center line. I frequently eyeball this but if you have a framing square you can get a good 90 degree center line. Next comes the hardest part. Don't move the end nail that is in the ground. Swap the middle nail with the unused end nail and walk with the middle nail to one side. When both strings are taught you will have made an equilateral triangle the center line. If you remember trigonometry an equilateral triangle has all sides the same length and all angles are 60 degrees. Stick the center nail in the ground and paint your side line. Finally, pull the middle nail and walk to the opposite side of center leaving the two end nails in the ground at the center line. When the lines are taught you will again have an equilateral triangle. Place the middle nail in the ground and paint the other side line. Once I am done I pull all the nails let the whole mess dry and save it intact for next year.

It really is a lot easier than it reads. I will try to take some pictures next month when I do this.