This a method to use to maximize your wins and minimize your losses if you find you are near-even or making a profit playing the game. I wouldn't recommend it for a newbie to the game or if the numbers have not been falling your way recently.
Start out with a .50 straight / .50 box bet on each pick.
If you win a box bet, increase your box bets by .50 for the next 40 picks (not draws) if it was a singles box or 80 picks if it was a doubles box.
If you win a straight bet, increase your straight bets by .50 for the next 250 picks.
If you win again before the limit (40/80 or 250 picks) increase your bet again by .50 for the appropriate bet (straight or box) and start over counting your picks once again until you either hit again (and increase your bet by another .50) or until you have hit the limit of picks without winning.
If you reach the limit without winning, go back to the original .50 bet on straight or box.
Keep in mind that you are tracking your box and straight hit results separately.
Theory: You are using 50% of a .50 win toward a bigger win next time. You are also taking advantage of winning and losing streaks.
Try it on paper first to see if it can work for you.