first you have to look at how long your horses stride is. I personally like setting lines based on a 12 foot stride. This way a horse with a big stride can fit in it and a short strided horse has enough room to add a stride. You also need to account for landing and take off room, this is 6 feet for landing and 6 feet for take off.
I walk out [my strides are 3ft long] out the line in how many strides I want, then one more for landing and take off - hope that makes sense !
Gypsy & Scout <3Everybody is a genius. But if you judge a fish by its ability to climb a tree it will live its whole life believing that it is stupid. ~Albert Einstein