Buy coins from the mint, buy groceries and gas, buy items from Lowes, or HD adn then take them back and get cash...
Above all pay them off when they come due, and throw them away, or you will be in trouble fast.
1500 or 4000 is not a lot to spend in 6 months,on a CC. if you have the income to qualify for that card.
I see a CC bubble on the way...