Tip #1: Spread your rice or pasta out as thinly as you can on your placemat. Finely shred your meat and broccoli between your fingers and sprinkle it under your highchair. Make it rain couscous. All of these actions give the appearance of eating.
Tip #2: Parents are known for having the energy levels of a dead porcupine and dinner is when they are the most tired. Take advantage of their frailty by running out the clock. Most caregivers can only put up with about 45 minutes to an hour of dinner shenanigans before they throw in the towel and wash their hands of your health. You know you've won when you hear them say phrases like, "Screw this" "I'm done" "Whatever" "I don't care anymore" "I hate my life" "Why are like this" or "I give up." :)
Tip #3: Still at the table? Shed some crocodile tears, son! Need inspiration? Act like that roast beef just set your favorite stuffed animal on fire. Pretend those mashed potatoes contain arsenic. Imagine your ravioli trying to choke you out. Get scared. Get loud. Get crazy.
Good luck. And don't forget to ask for dessert. You've earned it.