Step 1: Align your fabric along two perpendicular lines
Lay the fabric you plan on embroidering on a flat surface which has two perpendicular lines, in this case I am using a cutting mat as my reference. Square up your fabric along a vertical and horizontal line.
Step 2: Align ruler over fabric
Lay ruler over fabric and line up both edges of the ruler along a horizontal line of your cutting mat or other reference guide. Use fabric chalk or pen to draw a line along the ruler.
Step 3: Attach hoop and grid guide
Place the hoop on your fabric without tightening the hoop. Place the grid guide over the upper portion of your hoop and move the fabric around until the line drawn directly on the fabric lines up with a horizontal line on the grid guide.
Step 4: Tighten the hoop
Remove the grid guide and tighten the hoop over your fabric.
Step 5: Start embroidering
Once you have tightened the hoop, attach to the embroidery machine. Your image will be parallel to the top and bottom of your fabric.