Do you know about 0-3-6-9 in Pick 3? You should. The 4 digits can be used by them self as a single, 0xx, 3xx, 6xx, 9xx. As a pair 03x, 06x, 09x, 36x, 39x, 69x. Or not at all xxx. X= 1,2,4,5,7,8.  Now if you pick one of the digits 0-3-6-9 as a single the other 2 digits are 12,14,15,17,18, 24, 25, 27, 28, 45, 47, 48, 57, 58, 78. That's 15 combos max to play for a box hit! If you play them as a pair the 3rd digit is 1,2,4,5,7,8. That's 6 combos for a box hit.  How to play. If you think an 0-3-6-9 will repeat, just add the 15 pairs to it. If you think an 8 will repeat, play the pairs with an 8, 18-28-48-58-78. Then add 0-3-6-9 as the 3rd digit. If you think a 5 will repeat, play the pairs with a 5, 15-25-45-57-58, then add 0-3-6-9 as the 3rd digit for 20 combos max, and so on with all the X digits. The amount of combos can be reduced with consecutive pairs or not, mirror pairs or not, all even/all odd, series, etc. You do not have to play all the pairs. Do what you can afford.

You can also do this with the Pick 4.

If you use 0-3-6-9 as a single, your triads would be, 124-125-127-128-145-147-148-157-158-178-245-247-248-257-258-278-457-458-478-578 Total 20. If you use 0-3-6-9 as a pair, then the other 2 digits would be, 12-14-15-17-18-24-25-27-28-45-47-48-57-58-78. Total 15 pairs, same as with the Pick 3.

For Pick 4 doubles, if you think 00-33-66-99 will be the dbl, just add one or more of the 15 pairs.

If you think the dbl will be 11-22-44-55-77-88 you have 3 choices for the other pair. 1) Make a pair by combining one of 0-3-6-9 with 1-2-4-5-7-8. Add this pair to the dbl. Five combos to play. 2) Use  one or more of the 03-06-09-36-39-69 pairs. 3) If you don't think a 0-3-6-9 will hit. Use the 15 pairs. When using the 15 pairs eliminate the pairs with the dbl #. Ie, if playing the dbl 22 eliminate the pairs containing a 2. Ten pairs to play. 

The amount of combos can be reduced with consecutive pairs or not, mirror pairs or not, all even/all odd, series, etc. You do not have to play all the pairs or triads. Do what you can afford.  Good Luck!!!