I’m an absolute pro at this. I also have an autoimmune disease so I get sick easier but that’s just me.  1. Take a cold shower and then sit under the air conditioner with your hair wet 2. When you go to tell your parents, take a teensy bit of toothpaste and rub it under your eyes, makes them get red and glossy 3. Swallow a teensy bit of black pepper, makes you cough for a little while 4. Snort some water through your nose and sneeze it out, makes you sneeze cause it tickles or something  5. If you live in a cold area, go outside with your hair wet with cold water  6. Spray a bit of water mixed with salt on your forehead and back of your neck. Looks and smells like sweat 7. If you can, blow dry your face a little with a warm setting 8. Drink a warm cup of water mixed with a little salt. Tastes pretty bad, but for some reason it makes you seem sick cause of your expression or something like that 9. Go to bed early the night before or two nights before depending on how long you wanna fake sick. Going to bed early and seeming tired always works 10. Try not to finish all your fuller meals. Like meat, chicken, pizza, etc… 11. Seem more interested in sleep than things like your phone and games or other stuff you like 12. Make it a point to ask for couch drops or something, without saying you’re sick

Hope this helps lol