After you’ve followed the steps in the link above, start using Match on your iOS device by going to Settings > Music and turning the “iTunes Match” option on. After you’ve done that, you’ll note that a new choice will appear, labeled “Show All Music.”
If you leave that on, everything that’s been included in iTunes Match from the library on your computer will show up on your device, whether you have downloaded it or not (and whether you want it there or not!).
If you toggle “Show All Music” off, though, only items that have already been put on your device will show up. To snag a song out of the cloud, you can toggle that setting back on, download the stuff in question, and then turn it back off. Easy as pie, my friends. And for me, that’s much better than seeing all of the silly music I’ve managed to accumulate over the years. I mean, I want the option to be able to get my Debbie Gibson tracks whenever I want, but that doesn’t mean I need to look at them all the time.