(If you've never played MASH, I recommend looking up a video of how to play. I find it's easier to understand by just watching how it's done)
I start the lesson with a quick review of the future tense (e.g. I will go to the store, tomorrow; I am going to be a doctor in the future.)
I then do a demonstration of the game on the blackboard using my JTE as my partner. I only write the first two categories on the board and demonstrate how to do the spiral and how to count through the game. I then show them the powerpoint to explain what MASH stands for visually. I start by asking what the first picture of the powerpoint is in Japanese (looking for the answer マンション), then show them what "Mansion" means in English. My students always get a kick out of the difference in the English meaning versus the Japanese meaning.
Have the students partner up and pass out the worksheet. After handing out the worksheets, have the students write their names and fill out their own blank spaces at the bottom of each category. I like to encourage them to be creative by telling them I want to live on the Moon, have a pet unicorn, etc.
After you've given them some time to fill out they're worksheets, have them trade papers with their partner and take turns drawing the spial in the circle at the bottom. The student who the fortune belongs to will tell their partner when to stop drawing the spiral. The number of lines going from top to bottom in the spiral is their "Magic Number."
Using the "Magic Number," start counting from the "M" in MASH at the top of the page and crosses off the answer that they land on. For instance, if four lines were counted in the swirl, every fourth answer is crossed off the list. This continues until there is only one item in each category, the last items in each category being the player's fortune. Each letter in the title MASH is considered an answer and should be crossed off accordingly.
Once the students have found their partner's fortune, they can read it to them (make sure they're using the proper grammar: "You will live in a shack. You will live in Paris, France. You will be a teacher..." Then they can trade back their worksheets and write out their own fortunes on the back of the worksheet (I print this as a two-sided worksheet.) If there's time at the end of class, ask for a couple of volunteers to read out their fortunes for everyone to hear.
I would make sure to explain the rules well to the JTE beforehand, because the first time playing MASH can be a bit confusing.
I made the first item in category #1 the town my school's in.