This two-deck game is a easy variant of Forty Thieves. With good play you can win well over half of your games. Games of this type are interesting in the way the discard pile first grows, then (in a successful game, at least) shrinks again. The two keys to success are knowing how to transfer builds by clever use of empty tableaus, and knowing when not to make an obvious play because it might block a more important play later.
Because an 8 can be played on most 9’s, it is easy to swap cards from one tableau to another once you have a few empty piles. Use this swapping to make room for cards from the discard pile: if your only exposed 9 is a Club but you want to play an 8 of Clubs, swap some other (non-Club) 8 onto the 9 of Clubs, exposing a different 9 where you can then put the 8 of Clubs.
You can also use this swapping technique to expose cards that can be moved to the foundations, which in turn helps you make more empty piles.
In general, try to play low-ranked cards at first, and let higher cards sit in the discard pile.
Late in the game, use empty piles to reduce the size of the discard pile.
As a shortcut Solitaire Till Dawn will let you move full or partial builds provided you have enough empty piles available to have accomplished the same move one card at a time.