All cards are not created equal.
You've got a coin, a scratch card and crossed fingers. While everyone hopes for the big prize, any prize at all can make you feel great. While there's no way to change the odds, there are ways to play that make the game more fun and possibly more rewarding.
Look at the Back
All cards are not equal, even if they cost the same amount. Ask the clerk if you can look at the backs of some of the cards you're considering purchasing. The exact odds for each particular card are listed on the back. The odds vary somewhat, so pick the one with the best odds.
Pay More, Win More
Check out the odds on a variety of cards, not just the ones that cost the same. Usually, the higher the cost, the better your odds of winning. For instance, the odds on a £6 cards are almost always considerably higher than a 60p card. However, you're spending 10 times as much.
If you're more interested in the big jackpots, ask the clerk which cards have paid off big of late, and avoid those cards. There is a limited number of big prizes for each type of card, so buy a card that hasn't seen a jackpot winner in a while.
If there's a new card on the market, try buying it for a while. The odds of a new card's jackpot being claimed right away are small.
You won't find money giveaways at the convenient mart, but you can find them online. Many lottery and gambling sites either offer a first-time player giveaway (typically about £3) or a double-deposit if you join. The double-deposit means that a site will match your deposit up to a certain amount. They usually cap out at about £16. But that's still £16 worth of playing money for free. Two popular sites are Scratch2Cash and Jackpot Joy.
Whether you're buying your scratch card at a convenience centre or you're playing online, keep basic gambling tenets in mind. Play within your budget, set a limit and never chase money you've lost. In other words, if you can afford to play £3 per week, and you lose that £3, don't play again until the next week no matter how sure you are that the next one will be a big winner. Also, don't buy based on how a card looks, as it won't change the odds printed on the back.