For a Blackjack beginner, the best approach is to first learn and stick to the basic strategy, which outlines the best decisions to make based on your hand and the dealer's upcard. Focus on flat betting, meaning you wager the same amount each hand to minimize risk and prolong your gameplay. Keep your bets small, ideally 1-2% of your bankroll per hand, to avoid large losses. It’s wise to avoid complex betting systems like Martingale, which can quickly lead to significant losses. After a series of wins, you might cautiously increase your bet slightly, but avoid jumping in with large wagers. Also, steer clear of side bets and insurance, as these typically have a high house edge. Lastly, set clear win and loss limits for yourself before you begin playing, and always know when to walk away to protect your bankroll.