Waffle stitch, a needlepoint stitch, is a variation of cross stitch. In this stitch, each block has 3 diagonal stitches instead of just one. If the lines are vertical/ horizontal instead of diagonal, this is called a broad cross stitch.
Start with 3 parallel and diagonal stitches as shown below.
As you can see, the stitch in the middle will be longer.
Next, add 3 more stitches in the opposite direction.
This stitch can be used as a filling stitch or as a border stitch.
Add more blocks. In this example, I am going to use two colors.
This is a common mistake that is committed while doing any kind of cross stitch. As you can see below, the stitches are not traveling in the same direction. This will look bad especially if the project is a large one with a lot of stitches going in opposite directions.
To give a smooth finish, make sure the stitches travel in the same direction.
Adding a second color to fill the gap.