The outside edge of the stake should just touch the line.
String line fence post.
Well this is where you have to sort of take a guess or at least i did.
The lower string is to the ground without touching the ground the better.
For me building a fence starts with getting posts plumb and in a laser straight line.
Use a string line level or bench level to make sure the line is level then check to see that.
I like to use fast setting concrete for these posts.
The longer the run the tighter the string needs to be to stay straight.
At this point you pull the string to where you are placing the opposite end post.
How do you know you are parallel with the property line is the fence actually on the property line.
Drop a post into each hole and line its face up with the string while you plumb it.
Corner posts should be buried deeper to the ground at least 2 3 of the entire length of the post compared to your line posts at least 2 feet.
Mark the positions of the line posts and dig a hole for each one directly under the string.
Hammer your stakes in clear of your post holes so that the stakes are not disturbed during digging.
To ensure the posts are even in height run a tight string line between corner posts and end posts.
In other words the string will run where the fabric or wood pickets will be located.
Measure the positions of the posts with a tape measure and drive a stake at each point.
This can easily throw your fence line out of alignment.
Stretch mason string between the centers of all the batter boards to delineate the perimeter of the fence.
The following formula will help you compute the number of fence posts you need.