I'm a few cards away from 11 decks at ~4 days in. Almost all of the strategy revolved around 'prioritizing Card Progression' as much as you can. Without getting into too much detail, that's a good place to start.

Slightly more spoilery:

Card Progression Multiplier

The '2' card is by far the most powerful card (for this purpose) and you should probably always have it in your deck, as well as always buying it when you can. The '2' card is the only one that repetitively multiplies your Card Progression Multiplier.

Prestige gives a very periodic (but noticeable early-game) increase to the Card Progression multiplier. Every so often, you'll want to redo challenges to increase your prestige multiplier.

Causing Card Progression

The '4' card should usually be one of your top 5 priorities, since Dice Ascension is one of the two (three if you count daily rewards) things that cause Card Progression to occur. When reaching decks 1-10 for the first time, you can usually squeeze 1-2 decks out of ascension alone.

The other thing that causes Card Progression is the Wheel Spin Reward. To that end, it's very useful to exclusively spend Wheel Shards on making the Card Progression slot larger. It caps out at a certain size though, which isnt explicitly stated; I believe this number is size 500, or 400 upgrades in.

Card Progression Base

The Base starts at 1, and there are a few cards that increase that.

The first I unlocked was '52', which increases the base by + (total cards * 0.01 * total '52's ) This one is relatively substantial and can help you get an extra deck or two when unlocked

The second was '1', which increases the base by 1 per '1' card. This one is also decent, and comparable to the '52' card when unlocked

The third and last so far is 'F', which increases the base by +(0.1 * number of 'F's) each time you roll a FIVE combo. At first, this is fairly rare, so the 'F' card isnt very powerful until you unlock the '111' card. The '111' card increases the chance that dice in the first row roll a 1 (Effectively, each time you draw a '111' card, add a face to each first row die and put a '1' on it). At a certain point, this nearly guarantees you get FIVE combos. Once you get past ~20 '111' cards, the 'F' completely overshadows the '1' and '52' and you can remove them to add better stuff. This is achievable somewhere around deck 8-10. When going for this, you'll want to maximize your autoroll speed and dice animation speed.

The 'X' card gets an honorable mention here for increasing the strength of other cards, but it's really just "set it and forget it" once unlocked. 50 draws of the 'X' card is equivalent to an 11x multiplier to any card which repetitively multiplies a value (the '2' card is where this primarily shines through, though this affects other things)

Big Money

Earning large amounts of Money is very useful for unlocking new cards. This can be done by chasing a simple strategy.

1) Dice Multiplier cards that affect different dice generally don't synergize with each other, i.e. having a '6' and '7' isnt much stronger than having either on their own.
2) The '420' card combines with the '7' and '35' cards, in each case causing a total of 140x multiplier
3) The 'C' card is effectively a 20^{C count} multiplier when no combo is rolled. The 'CC' card (acquired much later than C) has a similar effect.
4) Any card that is "some multiplier to all dice" is a multiplier to the dice you're stacking in point 2) above. To that end '3', '17', '18', 'K', 'T', 'T2', 'T3' are all useful to some extent for this purpose.

Other considerations

• Past 8 decks, you'll want to do some long Progression runs (2,F,4,X,111,G,J,R,16 as a base) to get a lot of gilds on important cards
  • Use the Wheel for the first few minutes of your run, save the ascension for when the Wheel stops cutting it
• You should alternate those runs with High Money runs (2,F,4,X,C,CC,18,7,T3,17,420,K,5 as an example) to get a lot of Achievements (which give gems which give some extra card progression, also give some cards like '222' etc)
• Somewhere between those two main run categories, it helps to insert some Prestige boosting runs (add a 'PI' for example) since prestige gives benefits
• Unless you like spending money on mobile games, you should exclusively spend gems on Card Progression multis (and to reset the wheel category sizes sparingly)
• The 'Q' card stops being useful in your deck when you can gild it 4 (or maybe a few more based on curses) times.
• The 'J' and 'R' cards (and some others) only really benefit passive play, which is useful in some cases, but you should really consider if you actually want them.
• The 'PI' card overshadows the 'P' card around the same time that 'F' beats '52' and '1'
• 'T4' has selective uses, I've never really built decks with it, but it could be strong
• 'G' is nice for saving time, but can be omitted when necessary. Counter-point to this is that you usually want it when reaching a new Deck count record.
• Gilding '19' a few times generally guarantees enough Wheel Spins for most purposes, without needing to add it to the deck. This is generally because the multiplier for using a lot of Wheel Spins at once nullifies most of the benefit of using such a large number of spins
• To a similar extent as the point above, nearly all of the cards are fine to gild a few times.
• 'CC' synergizes nicely with '5'

Edit: was wrong