Faeria

So, first off, some stats.

Playing a game of Pandora either costs 2 regular chests or 2400 shards. I believe it is better to play with the chests.

The rewards for single player chest Pandora (as it is difficult to find enough players online to make multi-player finishable in a respectable amount of time)
*0 wins - 1 chest & 3 commons
*1 win - 1 chest & 3 commons & 1 rare
*2 wins - 1 chest, 4 commons, and 1 rare
*3 wins - 2 chests, 4 commons, and 2 rares
*4 wins - 2 chests, 5 commons, and 2 rares
*5 wins - 2 chests, 5 commons, and 3 rares
*6 wins (max) - 3 chests, 2 commons, 3 rares

Now, your first 10 (or more) runs, you are going to want to play for 6 as there is an achievement for going 6-0 ten times. However, after that, you have twenty more runs to complete, and based on the above, I believe 3 is the optimal number of wins. The rewards for 4/5/6 aren't that exciting, and at 3 you get your buy-in back plus 6 cards (which, their rarity is somewhat irrelevant, because the more commons/rares you block off, the better odds of opening epic/mythics). So win 3 games, hit the quit button next to the stalls, scoop up your winnings and repeat.

As for general strategies for Pandora:
*Stick with 2 color decks for the most part. One of the four will be turned off for the draft (hence the 3 gems that light up on the opening animation) Drafting all 3 colors will make messy openers. You can force mono-color, but it rarely appears worth it.
*Remember that once Pandora awakens, you'll be netting 6 mana a turn plus wells. So your curve can be a little high. And, at least for me, Pandora tended to hit rather quick.
*Like most other card game, the best value cards are the ones that make an immediate impact on the board state. Taunts, creature removal, gift triggers, etc. Vanilla creatures aren't terrible in this game, but can get trumped rather easily.
*As the AI is relatively poor IMO, trading creatures is preferable most of the time from pushing for damage. Limiting the computer's win cons usually yields better results then just going face. If you happen to trade a 4/3 for a 3/3, so be it.
*Finally, make sure taking the 3 squares in front of your orb is a priority once the computer pushes towards your side. No reason to let them summon creatures right on your doorstep.