If you're married, or planning on marrying their favorite child, you're already at a disadvantage with possible future in-laws. Then, being on their bad side could make the rest of your life a whole lot more difficult, so impressing them is your first priority.
Here are some totally serious and non-satirical tips to help you leave the best impression next time you see your in-laws.
1. The father-in-law will be paying attention to the roughness of your hands.
If you have soft hands, squeeze a few drops of super glue onto your palms before the handshake. Make sure to give it time to dry.