So I was perusing a woodworking group page and read a post from a member that stated, she was a total beginner, had limited tools but was up for a challenge. Her project required repetitive 45 degree cuts. She had a jigsaw and thought she could get hold of a skillsaw. She asked the question,"How does one make 45's without buying a ton of expensive tools?"

My answer: A 45 degree miter jig and this is how its made.

Step 1: Get the Things You Will Need

Plywood or solid stock that is approximately *6"x24"x 3/4" for the main body
Plywood or solid stock that is approximately *2"x24"x 3/4" for the riser block
Plywood or solid stock that is approximately *2"x14"x 3/4" for the saw guide. *These dimensions worked for her project. yours could easily be sized up or down to fit your needs.
The saw you plan on using with the jig.
A speed square or protractor
Fasteners and a way to use them. For example, a nail gun and nails, hammer and nails, screws and driver, glue and clamps, bubble gum and baling wire, what ever you have on hand.
A pencil.
15-ish minutes
The beverage of your choice (proper hydration is important).

Step 2: Attach the Riser Block to the Main Body.

Make sure one end and one long edge are flush to each other.

Step 3: Use Your Speed Square or Protractor to Strike a Line.

Start from the doubled up corner of riser block and main body and strike a line at 45 degrees.

Step 4: Offset and Strike a Secound Line

Offset 3"-5" (depending on how wide your saw base is ) and strike a second line parallel to the first.

Step 5: Attach the Saw Guide

Align the edge of the saw guide with the second line and secure it. Accuracy is very important.

Step 6: Cut the Mitered End.

Run the saw down the saw guide and cut off the square end leaving a mitered cut.

Step 7: Take a Break and Enjoy Your Beverage

You just made your own tool.

Step 8: This Is What the Jig Should Look Like

Step 9: This Is What It Should Look Like With Stock in It.

Some Final Thoughts: This tool can be made to fit right or left handed users. This is an unsophisticated yet highly accurate way to cut a miter. It has been used in different configurations for generations. If you are in a major miter jam this tool just might get you out.

I have a lot of respect for the woman that asked about this. She had courage to ask for help. She has the boldness to learn something new. She has the drive to creatively solve problems. These are some of the traits that make a great carpenter. With this tool she can build her skill, confidence and hopefully her bottom line so she can buy a compound miter saw and make the whole operation a lot easier. Until then...

Thanks for reading along. This is my first Instructable. I hope it was helpful. if you have any questions or suggestions feel free to comment.