Steal an Answer
During the questions section the host asks questions to the contestants in multiple choice format. Turns are given based on performance, with the person providing the first correct answer given bonus spins. Unfortunately, you may not always know the correct answer, however, you can "steal" or utilize your opponent's answer if you think his answer to the question is correct. This can be a smart strategy especially if you suspect the person you are competing against is smarter than you.
Skip Your Turns
While game play dictates you utilize your turns, if you are trailing dramatically in total of number of spins going into the board spin section, the skip your turns tactic can be a great way to cheat your opponent out of cash. The person with the highest number of spins goes first and when it gets to your turn, you can decide how many turns you want to spin. Since Whammies drop your opponent's cash to zero, you can pass your turns to him in hopes that he lands on a Whammy. Furthermore, if your opponent accumulates a total of four Whammies, he is permanently knocked out of the game.
Know the Questions
Getting a lot of turns can be highly lucrative during the game, and the only real way to ensure you have lots of turns is by answering questions correctly before any of the other participants. Asking the party host or the show to provide you a list of potential question topics is a great way to get a leg-up on the competition. Game shows will often provide a list of question topics prior to the competition and studying these topics beforehand will ensure you have an edge when it comes to getting turns.
Considerations
While these techniques can cheat your opponent out of a win, they are all very situation-dependent. For example, if you built up a large cash lead in the early rounds, then you may want to answer questions wrong and limit how many spins you have in later rounds. Furthermore, if you know your opponents have lots of Whammies, you may want to get a lot of turns so you can pass them and hope they both accumulate four which would make you winner by default.