Depending on what you are planning to do, there are several options. @Rin Rio-Oki showed solutions for when you are planning to build a fence-like structure, but if this is supposed to be a solid wall, here are three options:
The option furthest back is where you use a 1x1 brick with side stud and a tile in the corner. You could alternatively replace one of these with a headlight brick and a cheese slope if you want the corner to have an angle.
The middle option and the front option use a Technic 1x1 brick as a jumper (as it has a hollow stud on the top) to put the top plate in line with the bottom plate, which then allows you to line up your other bricks with the corner. Two different solutions for this are shown. I have color-coded the bricks for ease of reference (right side of the picture shows all the bricks used).