BobP's suggestion applies to online betting where you get 900 to 1 and it requires 5 hits a month to make a small profit. Most state lotteries pay 500 to 1 on a straight hit so you can only make 250 equal amount wagers in a month to get even money with only 1 straight hit. That averages out to be 8 straight combos a day and you could use a variation of Jap's H/L - E/O strategy.
There are 2 odd and low digits (1,3) and 2 even and high digits (6,8). Those 4 digits represent 64 straight combos but before deciding how play them, check your past history to find out if there were 12 hits in the past year. If there was, you have the basis of a playable system. I used those 4 digits because you can track H/L - E/O to determine which of the two digits to use in each digit position.
There are 8 different ways you can use 2 digits in each position to get 8 straight combos a day to play.
(1,3)(1,3)(1,3) (1,3)(1,3)(6,8) (1,3)(6,8)(1,3) (1,3)(6,8)(6,8)
(6,8)(6,8)(6,8) (6,8)(6,8)(1,3) (6,8)(1,3)(6,8) (6,8)(1,3)(1,3)
$8 a day for a month would cost $240 or $248 and with one hit a month at $500 will give you an even money profit. There are many other methods for picking the 2 digits for each position or you could add another digit in one of the positions and play $12 a day. That of course would cut into your profits.