The 'bet sizing trick' is a personal strategy where you start with the same bet for the first 20 to 30 spins, and if you don't get a big win or bonus, you double your bet for the next 20 to 30 spins. After a big win or bonus, you reduce your bet to a third of what you were betting for the next 30 to 75 spins, then rinse and repeat the process.