Creating a "single lesbian 40-year-old middle school art teacher" haircut on yourself can be a fun and expressive DIY project. This style might evoke a sense of practicality, creativity, and a touch of edginess. Think textured layers, maybe a bit asymmetrical, with enough length to play with. Here's a simplified guide, assuming you're aiming for a medium to short length with some personality:

Tools You'll Need:

• Hair clippers with guard attachments
• Haircutting scissors
• Comb
• Haircutting cape or towel
• Mirror setup (one large mirror in front and a handheld or another fixed mirror behind you)

Preparation:

1. Wash and dry your hair. Clean hair is easier to cut and style.
2. Choose your length. Decide on the overall length you're comfortable with. This will guide which clipper guard you start with.
3. Set up your mirrors so you can see both the front and back of your head with ease.

Cutting Process:

1. Initial Trim (Clippers): If your hair is long, start with clippers and a higher guard number to trim down the bulk. Move against the direction of hair growth. For a more layered, textured look, switch between guards to vary length subtly as you move around your head.

2. Top and Front Section (Scissors):

   • Comb your hair and identify the top section.
   • Take small sections of hair between your fingers, pull it away from your head, and trim to the desired length. Start longer; you can always cut more off.
   • For the front, consider how you want your bangs/fringe. Do you want it straight across, side-swept, or more pieced out? Trim accordingly, keeping the scissors angled for a more textured look.

3. Sides and Back (Scissors and Clippers):

   • Use clippers with a guard for the back and sides to achieve a cleaner, shorter look if desired. Blend into the top by gradually changing the guard size.
   • For a softer, more textured edge, use scissors to cut vertically into the hair (point cutting).

4. Detailing:

   • Check for any uneven areas and clean up the edges around your ears and neckline with the clippers without a guard or with a very low number guard.
   • Personalize your look by adding more texture or asymmetrical elements as desired.

5. Styling:

   • Once you're happy with the cut, wash your hair to remove any loose hairs.
   • Dry and style as usual. You might want to use a bit of product to enhance the texture or hold the style in place.

Tips:

• Take your time: Rushing can lead to mistakes. Cut conservatively, as you can always trim more off, but you can't put hair back.
• Regular Maintenance: Keeping your new style looking fresh might require more frequent trims, especially for the back and sides.
• Inspiration: Look up images or videos for visual guidance. While your cut will be unique, having a reference can be helpful.

Remember, cutting your own hair is a skill that takes practice. Embrace the imperfections—they add character to your look. This haircut is as much about expressing your individuality as it is about the physical style. Enjoy the process and your new look!