This is rather straightforward, just load up the game, start a new Splat Jaypack's Arena game in Normal difficulty, and you're set.

If you have your eyes on the Hoarding achievement (win the first 4 fights without buying or selling any item), obviously do not buy or sell any item then.

The Finally Free achievement is one of the easiest to get in the game, yet funnily enough Steam stats show a 0.6% rate.

As soon as you've loaded into your new game, head to the rest room where your extra companions are.

Kick out the Dwarf and the Elf, recruit the Minstrel, Paladin and Priestess and poof, the achievement is yours, you don't even need to do a fight at this time.

You may want to speed up both your characters' and the AI's battle animations so the upcoming battle takes less time.

You may never have noticed it, but there is an option just for that in the gameplay settings.

Scroll down past the "mute the dwarf / mute the elf" toggles and find the animation speed, crank that up for your party members and the AI.

The Staff Cut achievement will take a bit longer, but you'll notice it's as easy as the previous one.

Rearrange your party to the following :

• Barbarian
  
• Dwarf
  
• Ogre
  
• Priestess OR Wizardess

Now what you want to do is set them up nice and cosy in a square formation, with your 3 frontliners protecting the Priestess/Wizardess and preventing enemies from reaching her, as follows :


On your frontliners' turns, spam the Protect/Defend action to raise their armor and parry/dodge chance.
On the Priestess/Wizardess' turn, use your ranged attack to clear out the 2 humans, then the chickens.
Use the healing spell in a pinch.

The fight will take quite some time to finish, but it'll be an easy unlock for sure.
Enjoy :)