Just thought I would drop off some tips on building a fence that is straight and stays straight for years.
If you are planting a fence where the soil has been disturbed, soak the crap out of it and let it dry out so it settles and compacts.
One third of the post must be in the ground or to the depth of the frost, if you are using concrete the hole should be straight or slightly larger at the bottom, never bring the concrete to the surface.
If concrete flairs at the top, the frost can get under that edge and lift the post.
We cut the post to height after the fence is built.
We plant the two end posts first and stake and brace them plumb.
We run a tight string between those about 5 inches above the height of the panel.
We screw a panel to the first post and then screw the next post to that, crown the post so it crowns toward the panel.
We stake and brace the top of the post so it line up with the string, brace at the same height as the string.
We adjust the bottom of the post so it is plumb add another brace and add concrete, remove the lower brace.
We only dig one or two holes ahead as the measurements always seem to get screwed up and the holes get bigger.
We cut the last panel to fit or if you are building your own you can do the math to make them all the same.
There were three contractors in our neighbourhood building some eyesores before we were asked to build one. As this is our hood we made sure they were straight and plumb and they still look great after a few years, other guys, not so much.