For these achievements, just play the game. By the end, you'll have all of these regardless of what you do.

The Convent

Finish chapter one.

Edna's Hideout

Finish chapter two.

The Asylum

Finish chapter three.

Hare Scare

Defeat all Harvey's.

Role Play Gamer

Sleep!

Fast Learner
I don't need no tutorial!

-- As the description hints, at the very beginning of the game, when you are asked if you want to go through the tutorial, select 'No'.

Sisyphean Labor
How's that supposed to help?

-- During the opening scene of the game, continue to rake the leaves until you get the achievement without raking the stone slabs which would continue the story.

Shibuya Power
Shibuya Power!

-- In the dormitory, when you speak to either Suka or Sky, they will begin the conversation with the phrase 'Shibuya Power!'. Speak to the girls about ten times, leaving the conversation each time, to get the achievement. This needs to be done when you first encounter them, before you show them the bomb and before Suka leaves.

99 (Red) Balloons
Floating in the summer sky.

-- The clown who gives you a balloon will give you a new balloon if you ask him for one. For this achievement, you must ask him for a new balloon a lot. Perhaps 99 times that the name suggests, but who can be bothered to count them. In good news, you don't have to leave the conversation each time. Just keep clicking around on the different balloon options.

Mnemonic Device
Help the old man.

-- Solve the janitor's puzzle instead of skipping it.
-- Note that there is an achievement for skipping all of the mini games. So you should save before each mini game, beat it for that mini game's achievement, and then restore your game and skip the mini game so that you can unlock the "Loathing Mini Games" achievement.

Heraldry
X marks the spot.

-- In the chapel, solve Frank's minigame instead of skipping it.
-- Note that there is an achievement for skipping all of the mini games. So you should save before each mini game, beat it for that mini game's achievement, and then restore your game and skip the mini game so that you can unlock the "Loathing Mini Games" achievement.

déjà vu
I think I've been here before...

-- From the graveyard where Miranja sits, there is a '???' hotspot on the left side of the screen that looks like you will be traveling down the path further. Click this hotspot to see a short cut-scene that references the first Edna & Harvey game.

Sun King
Even the sun follows by command!

-- From the western village, go to the area where the sundial and buzzard are. Click on the sundial to switch it's position about 15 times.

Coffee Junkie
I need more coffee! More!

In the dream/hypnotized/whatever areas, you will find various cups of coffee that allow you to leave the area. You need to drink the coffee about ten times to get this achievement.

Lady Justice
Justice Prevails

Complete the minigame in the jail about lying without skipping it.
-- Note that there is an achievement for skipping all of the mini games. So you should save before each mini game, beat it for that mini game's achievement, and then restore your game and skip the mini game so that you can unlock the "Loathing Mini Games" achievement.

Pathfinder
Find the right path.

Complete the Prairie minigame without skipping it.
-- Note that there is an achievement for skipping all of the mini games. So you should save before each mini game, beat it for that mini game's achievement, and then restore your game and skip the mini game so that you can unlock the "Loathing Mini Games" achievement.

Hoo Hoo
Hoo hoo. Whit woo. Terwit terwoo.

Complete the owl conversation minigame without skipping it (did you even realize you could skip it? I didn't at first.)
-- Note that there is an achievement for skipping all of the mini games. So you should save before each mini game, beat it for that mini game's achievement, and then restore your game and skip the mini game so that you can unlock the "Loathing Mini Games" achievement.

Row Master
Row, kid! Row for your life!

-- In the Asylum, get in the row boat and row from the far right of the right most screen to the waterfall on the left of the left most screen. You have to go all the way back and forth 5 times (far left screen to far right screen and back being 1 time).

Quick Time Event
They don't really have quicktime events in this game, right?

-- When grabbed by the phantom and the purple X appears on the screen, do not click on the X. Instead press the X on your keyboard and also click the ledge. You will see the X on screen change as if it has been pressed in, and will make a punch sound. Do this 15 times, then click the X, and then the ledge. You will get the achievement once Lilli pulls herself up.

Pizza Time
Did someone here order a pizza?

-- Use the following combination to complete the pizza puzzle. Red Bananas, Yellow Blueberries, Green Tomatoes, and Blue Broccoli. Note that some people do not get the achievement when using this combination. The common ground seems to be that those people attempted other combinations before trying this one. So it is more than likely true that you need to do this combination the first time.

Droggeljug
Droggeljug!

-- After completing the role playing section, speak to Droggeljug about ten times.

Fight Club
If in doubt - give him a clout!

-- After completing the role playing section, talk to Peter to punch him about 15 times. You might need anger management classes.

Cell Song
I hear someone singing ...

-- After completing the role playing section, go back to Miranja's cell and click on her. Talking to her will treat you to her singing and give you the achievement.

Checkmate
Defeat the Mother Superior.

-- Win the board game minigame instead of skipping it.
-- Note that there is an achievement for skipping all of the mini games. So you should save before each mini game, beat it for that mini game's achievement, and then restore your game and skip the mini game so that you can unlock the "Loathing Mini Games" achievement.

Multiple Endings
Multiple endings? I need to see 'em all.

-- Save your game after beating Mother Superior in the board game. When given the three options with the doctor, select one to see that ending, then reload and select another. Repeat for the third ending. For the 'Contradict' option, you must click on it 4 times to trigger the third ending.

Short Arms
Lilli's arms were too short.

-- There are several times in the game where clicking on something will give you the message "Lilli's arms are too short." Click on whatever gave you that message about 15 times to get the achievement. In act one, you can easily do this from the cellar window. If you happen to be in the Asylum, Chapter 3, trying to click on things while reaching through the grate in the maintenance room works.

Electric Shock
Aaaargh!

-- Any time you try to perform a restricted action, you get shocked. Do this about 15 times to get the achievement. The easily place to do this is immediately after being hypnotized. You are asked if you will make tea. Refuse until you unlock the achievement.

Super Girl
That doesn't apply to me.

-- Switch between the different restrictions a lot. You can do this anytime in the game once you have unlocked at least two restrictions.

Loathing Mini Games
I hate mini games!

In a single playthrough, skip all six mini games.
The mini games are:

• Chapter 1: Old man Mneumonic Puzzle. (It's from the old man hanging on what looks like a coat rack who talks about templars.)
  
• Chapter 1: Frank's Mini game in the chapel.
  
• Chapter 2: Get the gnome (or whatever) across the hills.
  
• Chapter 2: The lying game when getting out of jail.
  
• Chapter 2: Owl Conversation
  
• Chapter 3: The board game against Mother Superior.

In order to get all of the achievements in one playthrough, you will want to save before each mini game. Then beat the mini game to get its achievement. Afterwards, reload from right before the game and skip the mini game. Do that for every mini game to unlock all 6 of their achievements and this achievement in a single playthrough.