(Courtesy of Ryan Dancey on the Paizo Forums)
My Fighter build was designed to get the character to level as fast as possible, not to necessarily be a "fun" character to play on a daily basis. The Dreadnaught 2 trainer in the NPC Settlements doesn't know how to teach higher ranks of Base Attack Bonus so I would need to seek out a higher level trainer if I wished to continue to advance (and kill a lot more goblins).
I only used 2 dev commands. I gave myself a lot of XP, and at one point I added a nonmagical Hunter's Longbow to my inventory to save myself a trip to Thornkeep, or a bit more killing of goblins for random loot.
Hitting the Martial Achievement goals took about 4 hours of play and during that time I was working on other things as well not paying 100% attention to the goblin killing. It was pretty "casual".
I spent 29.21 days of XP. Since I reached all the Achievement goals in 4 hours, I think its pretty reasonable to say that at least for this build, the amount of time you would spend pursuing Achievements compared to the amount of time you could spend doing self-directed things is pretty trivial.
What I did:
I trained all my Feats at the Fighter College and the Dreadnaught School in a starting NPC Settlement.
The only things I killed were the Tutorial goblins right on the edge of town.
Heavy Blade Expert 4 (Steel Greatsword): Killed 100 goblins (10 Martial points) Longbow Expert 4 (Hunter's Longbow): Killed 100 goblins (10 Martial points) Hammer Expert 3 (Softwood club): Killed 50 goblins (6 Martial points) Polearm Expert 2 (Steel Spear): Killed 20 goblins (3 Martial points)
Goblin Slayer 5: Killed 270 goblins (15 Adventure points)
I did the tutorial and took the 3 Tutorial Feats. Trained Trophy Charm Implement Proficiency 1. Then I trained nothing but Power, Fortitude Bonus, Hit Points and Base Attack Bonus to increase to Fighter 7.
At this point I had 22 Martial points (Heavy Weapon 4, Longbow 4, Hammer 2).
At this point I hit the Strength gate. I trained all the Weapon Attack Feats for Heavy Blade and Hammers. I also took all the Master of Opportunity Feats. This cleared the Strength gate.
At this point I hit the Constitution gate. I trained the Armor Feats, the Shield Feats, and the various Feats like Bravery, Bulwark, etc. This cleared the Constitution gate.
Feats (final ranks):
Base Attack Bonus 4 Power 8 Hit Points 8
Bull Rush 2 Bulwark 2 Recovery Bonus 4 Bravery 2 Toughness 2 Great Fortitude 2 Fortitude Bonus 4
Master of Opportunity: Suffer 2 Master of Opportunity: Stand Still 2 Master of Opportunity: Stop 2 Master of Opportunity: Slip 2 Master of Opportunity: Stumble 2
Heavy Armor Proficiency Dragoon 5 Unbreakable 5
Medium Armor Proficiency Archer 5
Trophy Charm Implement Proficiency 1
Heavy Meele Attack Bonus 2 Heavy Blade Proficiency 1 Cleave 3 Cross Blow 3 Hoist 3 Passing Step Thrust 3 Swing 3 Wind Up 3 Wrath Guard 3 Wrathful Strike 3
Hammer Weapon Proficiency 1 Beat 2 Conk 2 Escape 2 Inertia 2 Shillelagh 2 Shove 2 Thump 2 Thwack 2
Shield Weapon Proficiency 1 Shield Bash 1 Shield Block 1 Shield Charge 1 Shield Slam 1
I never equipped armor. All goblins were killed with the 2 starting Feats you get with each weapon.
I slotted Toughness with the Tutorial.
No other Feats slotted.
Strength 11, Constitution 11
620 Hit Points Fortitude 16 Base Attack Bonus 13 Heavy Melee Attack 21 Light Melee Attack 13 Ranged Attack Bonus 13 Arcane Attack Bonus 13 Divine Attack Bonus 13
Notable Loot (lots of loot not listed):
270 copper, plus a bit I spent on Greatswords in the Auction House
Recipes for Pot Steel Plate, Quiet Iron Shirt, Steel Ingot +2, Warm Hat, Weak Antiseptic Extract.
I got as loot all the weapons I used except the Greatsword, but I ended up with 2 in inventory so if I had just been patient I wouldn't have needed to go shopping, and the Hunter's Longbow I conjured with dev commands.