Game Room

For this and the other challenge achievements, you can use another account on your xbox if you have one. A silver account will do. You do have to buy a game to be able to send challenges. But once you do, set it to an hour, most points, fail miserably on the second account, beat that score with your main, and voila, you won a challenge!

If you have another Xbox Live account(No Gold Membership required), you have quicker way.

Your sub-account should have 1 of games your main account have, or process can be done with same console.

Make 10 challenges with following setting:
Challenge Terms: Highest Score
Number of Tries: 1
Game Duration: 1 Minute
Challenge Expiration: 1 Hour
Then play challenges with both account. After playing with both account, each challenge ends quickly.

You'll complete 10 challenges(and unlock "Challenge Chief") about 30 minutes, and make another wave to unlock "Challenge Master".

In order to earn this one, you're going to have to need to purchase at least one game for your arcade. Once you do that, you can create challenges for that game against your friends.

Boosting is easy. You can have several challenges running at once. Your friends can also challenge you in return. Set the challenge to the shortest time possible, and win a token amount of points. Have your friend play the game and do worse. Voila! Challenge won. Win 20, and you'll get this shiny, then you can help your friend boost as well.

Obviously sending yourself requests from another account to your main account is the easiest solution. A silver x-box account will suffice.
Make sure the settings are as follows:
Challenge Terms: Highest Score
Number of Tries: 1
and
Friend: Select your main account that you wish to obtain this acheivement on OBVIOUSLY.
The rest of the settings don't really matter as long as you make sure you only have 1 try set.

Games I find easiest are ones that you can fail on fairly quickly such as Crystal Castles.
If you have the game set to highest points then simply run into the enemies until you're completely down and out on your side account then on your main account beat the challenge set!
Obviously there are plenty of games you can kill yourself on swiftly...(LOL)
Send 20 challenges with your side account and beat them all with your main account and you're done here!
AWESOME!

For me centipede was a great game to get this on. Once the challenge has been made with your alternate account shoot once, die three times and fail miserably. Then sign in with the main account, do the first level and win the challenge. Easy.