Despite the achievement reading career match it can also be done on exhibition mode and I'm sure on tournament mode as well for I recently went back to this game for the Grand Slam achievement and practiced using another account where it unlocked for that account during an exhibition match against Wayne Mardle in a best of 5 sets, 5 legs format.
For those unfamiliar with darts, a 180 is hit when all three darts land on the treble 20 which is the smallest red target located at 20. This is the maximum score you can achieve in a darts match. For this achievement, you need to hit more than 10 180's during a match.
The easiest way I found to hit a 180 is to aim at the top of the board as far as it'll go, then flick the right stick gently so that is gives it little power and 9 times out of 10, barring deflections that may occur it'll go into treble 20.
For obvious reasons you cannot hit 10 180's consecutively as you have to finish on a double to win a leg and hitting 180's continuously during a leg causes you to bust your score and these will obviously not count. So the most you can do in one leg is 2 if you are playing a 501 match.