In case you'd like to do this quickly, here's the quickest bunch I found. I've included several options in case you don't want to, say, grind out cockfights just yet. A very handy mission to replay is Mrs. Chu's Revenge, as it features melee enemies, armed melee, firearms, and driving.
FLUID STRIKER, DISARMS50 vault attacks, 50 disarms. Load up Mrs. Chu's Revenge, play through the melee sections, then get to the point where you need to vault over and into an enemy. This counts as both vault attacks and disarms. Restart checkpoint and it's a short sprint and vault.
HEADHUNTERScore 50 headshots. Any mission with guns is good for these.
LUCKY SHOOTER10 blindfire kills. You'll want something automatic like an SMG, machine pistol or assault rifle. Meet the New Boss is decent for this if you have health regeneration. Get an automatic, and when you have the shootout outside, run up closer and get in cover on the opposite side of their cars, then blindfire from close range. You'll likely have to restart checkpoint a few times.
FIRESTARTER10 explosive kills. Payback is a good option for mission replays, as when you get the gun, several enemies are conveniently standing next to explosive barrels, highlighted in red. Restart checkpoints to farm these kills.
SNIPERHave a 50% accuracy rate with your last 50 shots. Either go to a drug bust like Sun Yat Housing Complex in Kennedy Town, or load up Mrs. Chu's Revenge or Meet the New Boss and play to the end of the level. When driving away, aim at the cars and wait for the slow motion; as long as you hit the car, it all counts.
GUNMAN100 firearm kills. Once you've gotten to the point where guns are introduced, good luck
not getting this one.
NINJA10 instant takedowns from behind. Get the Leg Break move from the Jade Statue mission or the Surprise Attack move from the Triad upgrades. Use the combo on an enemy and it will leave them stunned with their back turned. Neither work on wrestlers, but only the Surprise Attack works on armed melee foes.
BONEBREAKER100 broken bones. The Leg Break move from the Jade Statue mission is invaluable here as well.
ENVIRONMENTALIST50 environmental kills. Whenever grappling an opponent, look for objects highlighted in red. Either press
near them or run them into it by holding
.
DEFENCE100 counters. This one's a given.
DEADEYE10 thrown weapon kills. Careful with this one, as if the thrown weapon hits you, it's an instant kill on yourself. Whenever you see a group of enemies while driving around, stop, find a car with a tire iron, and when they get close enough to fight, hold
to lock on, make sure you're looking in the right direction, then
to throw.
MARTIAL ARTIST100 melee kills. By the time I had 100 firearm kills, I had 400 melee; you should already have this one.
ENFORCER200 total enemy kills.
SAFE DRIVER30 minutes total clean driving time. This one's very dependent on driving a car around instead of a motorcycle. Use the racing coupe from the Hotshot case and the time will rank up slowly but surely. Use the High Roller Tuono from later in that case to start gaining progress towards Reckless Driver as well. If not, there's a circular road in the north of Central that you can easily drive around without hitting anything.
MOGULEarn $2,000,000. This won't be much of a problem between lockboxes and side mission payouts, especially Tran and Roland. Gambling also works, and unlike the Gambler award, this one doesn't count losses against you.
GAMBLERSave outside the cockfight at the north end of Kennedy Town. Bet the maximum amount on either cock. If you're down $200k from when you last saved, load your save back up. If you win and you've made money, save again. This award tracks up and down, so if you continue to lose, you lose progress. This will also earn you the Infowlable achievement.
PUBLIC ENEMY200 kills in a single play session. Martial Arts Club, Mrs. Chu's Revenge, drug busts, do whatever you need to do to keep that kill counter rising.