Mark the height of the pickets on your posts. Transfer the pencil line around the post. Use your saw to cut the tops off your posts.
Find the centre of your rail and measure the width of the picket. Mark the edges of the first picket so that the centre point of the rail sits in the middle of the picket.
Now, take your level and transfer your measurements to the top and bottom rails. This will ensure that your pickets are straight when you attach them.
Nail the first picket in place. Repeat steps 2 and 3 to position and fix the remaining pickets, working your way out from the centre. To work out the space between each picket, we have used the thickness of a picket.
When you get to the end of the run leave the last three or four pickets off so you can adjust your gaps to fit the remaining space. Lay the pickets against the rail and adjust spacing to suit. Mark the edges of each picket on the rail. Again, use your level to transfer these marks to the top and bottom rail. Then nail them in place.