If you get the large straight with the first roll, simply go for the large straight fill as they are worth more.

The small straights in early game must be played different based on the type of small straight and the pair associated with the small straight.

Small Straight 1-2-3-4 and 3-4-5-6 First Roll
With Pair of 1, 2 3, or no Pair:
Keep the small straight and roll.

With Pair of unfilled 4, 5, and 6:
Keep the higher value pair and roll.

If the small straight has been filled, always keep the pairs and roll. When the pair from the upper section has also been filled, keep the higher value dice only and reroll everything.

Small Straight 1-2-3-4 and 3-4-5-6 Second Roll
In second roll of early hands 1-4. Keep all small straights and go for the large straight.

Small Straight 2-3-4-5
Always keep the small straight and go for the large straight.