Hitman HD Pack

I'm going to disagree with the other solutions on how is best to get this. This is especailly helpful for those who have done a professional only run, as I did this on professional.

The achievement is 'Call The Caddy', and to unlock it you must make 18 kills with the golf club. This is obtained in the bosses bedroom in the first mission, "Anathema".

The kills are cumulative, you can make one kill, finish the mission, then you only require 17 more. If you die, or quit, kills are not saved.

Load up "Basement Killing", and take with you the Silverballers SD and the golf club. Drop the club straight away.

You now have around 8 guards to kill. You dont need to kill the ones at the back near the stairs.

I shot the 3 in the siderooms to the right, the 3 at the front lobby, and the 2 at the metal detectors. Then i went and picked my golf club up, and killed 18 civilians who can't fight back.

This way takes around 5 minutes, and I didn't fail. I also as mentioned, did it on professional. "Anathema" has too many guards with guns that you need to kill, so I'd avoid that personally.

This achievement is called "call the caddy" and it's for killing 18 people with the golf club. You can get the golf club in the first mission "Anathema". It's located in the bosses bedroom. Sneak or kill your way to his room and steal his club. Then either finish the mission with the golf club or just start killing 18 people. If you snuck in then there's plenty of people in this level to kill. If you went in guns blazing then there is moat likely not 18 people left in this mission BUT no worries because St Petersburg has plenty of people to kill. They are spread out a lot more in St. Petersburg as well so you won't be fighting for your life constantly if you choose to go this route.

Edit: this achievement is also cumulative. Meaning you can kill 10 people in one mission and then kill 8 people in another mission and get your achievement. HOWEVER you must finish the level in order for the game to count your kills. You can't get a few kills in a mission and then leave the mission or die or save and quit. You MUST finish the mission for the kills to count....except when your going for your final kills. It will pop as soon as you get your last kill and you won't have to save those kills.

This achievement is for killing 18 people with the golf club in Silent Assassin. You must get 18 kills in one level. Kills must be made in one play-through and are not carried over as cumulative; unless you complete the mission and kills are saved.

With that said, the easiest method of gaining this is loading up the first level Anathema on normal difficulty and sneaking up to the Boss' bedroom in order to get the golf club which is positioned by the bed and the night stand. Start getting your kills with the boss and his guards, being extra careful for the attorney in blue with a shotgun and the private body guards who carry Deagles.

On easy you'll have 6+ saves right off the beginning so you can save after getting 5 kills so if you do get ambushed your efforts weren't a waste of time. Including the staff, Anathema has about 24-25 people in it, depending on if you catch the delivery guy before he drives away. Another perk to performing this on normal setting is that everyone is visible on your map screen, again which helps you from getting ambushed and also helps find the civilians running around inside the rooms.