For doing this you need about 200g to start (recommended), 50g also doable.
So this is how I made some gold for my lvl 63 alt on another server:
With TBC there came new cards (Lunacy Blessing etc.)
So what I do every thing I log in is search for these:
Ace of
Two of
Three of
Four of
Five of
Six of
Seven of
Eight of
Now, here is the thing.
I buy every card (only the new ones) under 50g (unless there are alot of the same card).
This card will be putten back on AH for 99g bid and 99g.99s Buy-out.
Just to let you know: Ive got enough gold for my flyer already