The formula hubbs came up with is this: You figure out what size you want the "slug" or track and then the distance between the two tracks is half that and then the distance between the two tracks on the other side is 2.5 times that.
Here my plan for this border. Please note: some of the most basic details have been left out, if they need to be put in for clarity, please let me know.
I wanted a 6 inch border but I needed to make it look like tractor tracks in a 6 inch space so the smallest I could go would be a half inch so I decided that the track would be one inch, the small distance would be half inch and the large distance would be 2.5 inches but when I put it on there, that didnt look like a tractor track and so I reduced that one down to 2 inches. I added the extra for seam allowances and started to cut.
Heres what I did:
Cut a strip 1" wide, and 2.5" wide of the light tan, and a strip 1.5" wide of the dark and arrange them with the dark strip in the middle like this...
Then sew the strips together with a 1/4 inch seam allowance.
Then cut the finished strip into 6.5" blocks
and arrange like the friendship braid,
Lay one right piece and one left piece, right sides together, sew a ¼ inch seam allowance and you wind up with what looks like tractor tracks, but lets clean it up a bit.
Lay a 6" ruler down where the top tips of the tracks are hitting on either side of the center line like shown in the below picture.
I added an inch wide border on either side of the tracks and added it to my quilt. Looks good eh?
Enjoy this tut! Please let me know if there needs to be more details or if ive messed something up.