Measure the inside width of the window at the top, middle, and bottom
Measure the inside height of the window at the left, middle, and right
Use the smallest width and height measurements
Check the blind manufacturer’s size requirements
Gather a tape measure, pencil, drill, screws, screwdriver, and level
Mark the bracket locations inside the window frame
Make sure the bracket marks are level and evenly spaced
Pre-drill pilot holes if needed
Attach the mounting brackets with screws
Snap or slide the blind headrail into the brackets
Secure the headrail according to the blind type
Test the blind by raising and lowering it
Install any valance, wand, or cord safety hardware
Trim excess cord if required and safe to do so
Check that the blind opens, closes, and sits evenly