Just religiously put everything you can on the credit card. I actually kept a spreadsheet last year to track my spending, and we hit the $30k in late October. Going for another 2-4-1 voucher this year.

Some big expenditures on my card:

* Our 2 cats' vet bills for the year were $1700
* Paid our federal taxes which were about $2k
* Did $6000 in mint coins (didn't need to do any more)
* I organized a White Sox outing for friends that cost me $2500 and then they PayPal'd me back so I only spent $75 OOP for my own ticket.
* Comcast $1100
* Verizon and T-Mobile payments $500

So you can see right there that's about $14k.... then figure another $4k or so for normal grocery/gas spending... the rest was all incidental stuff like travel and shopping (no foreign transaction fees so we used the card in England and Belgium last year). Just try to think outside of the box, see if there's anything you can buy for friends or family and have them pay you back in cash or using PayPal. I haven't figured out yet how to pay my mortgage using any of my CC's, but trust me, as soon as I can, I will do that!