Note: Use the Advanced UI. Click "Switch to Advanced UI" in the top menu before starting.
This gives you two menus to play with: one along the top and one on the right. These menus are used to unlock most achievements.

Counter increases after the initial loading screen.



Self-explanatory.



Avatars aren't categorised by type anywhere, so there's no way to know what is considered feline/canidae/fluffy/scary. I suggest just switching to every avatar you own.
Below are my best guesses but I can't guarantee its accuracy. Personally, I had the following 14 Avatar DLCs installed, with the bolded ones probably needed for achievements:

• Legrand Legacy -- free DLC
  
• Team Fortress 2 Avatars DLC -- free DLC
  
• Octodad Free Avatar -- free DLC
  
• Starbound Free Avatars -- free DLC
  
• Halloween Avatars 2014
  
• Halloween Avatars 2015
  
• DreadOut Avatars DLC -- free DLC
  
• Live2D Module
  
• Winter Holidays Avatars 2015
  
• Trials Fusion DLC -- free DLC
  
• Warriors
  
• Strong Paws
  
• Political Avatars -- free DLC
  
• Pewdieverse DLC -- free DLC

Requires Strong Paws DLC.

Unsure if any DLC are required. Doesn't look like there are canidae avatars in any of the DLC though.

Requires Winter Holidays Avatars 2015 DLC.

Requires Halloween Avatars 2014 (?), Halloween Avatars 2015 (?), DreadOut Avatars DLC.

Requires free Team Fortress 2 Avatars DLC.

Requires Live2D Module DLC.

Download some custom avatars from the Workshop page before launching. Can just download two and switch between them.

Props can be accessed from the third tab in the Avatars window. Not all 10 props need to added to the same avatar for Popularity award.

Edit the any of the options in the 2nd (and beyond) tabs in the "Avatars" and "Environments" windows. Must customize 20 separate avatars and 10 separate backgrounds. Exporting the options to a file isn't necessary.

"Reset All Configurations to Default" button in the top menu. Press 20 times.

"Add text and image overlay editor" option in the right menu. Add text or image and save the layout to unlock the achievement.

Disable the Face Tracker, and modify some of the options in the "Pose Avatar" window in the right menu.

Load a 3D background (see the background's description to know if its 2D or 3D) and rotate the background around the avatar a full rotation. Default key binding is CTRL + Mouse LB drag. See key bindings in options and look for "Rotate around the Avatar".



Enable the "Toggle Audio based Lipsync" button in the top menu. Should be a slider bar with a lips icon in the top left when enabled. Can be combined with most other timed achievements.

Enable the "Toggle Broadcast" button in the top menu. Should say "Broadcasting" in the top left when enabled. Can be combined with most other timed achievements.

Enable the Face Tracker and point elsewhere/block the camera. Should say "Face Tracker Initializing" in the top left corner. Can be combined with most other timed achievements.

Add at least one voice effect in "Voice Effects" window (right menu). Can be combined with most other timed achievements.

Enable both "Enable Custom Actions" and "Show Custom Actions Panel" under the Behaviour tab in the Avatars window. This adds a window with four smiley faces to the main screen.
Click and drag the top right smiley to control your avatar's tongue. The bottom two control the hands.
Can be combined with most other timed achievements.



Self-explanatory. The "Screenshot" button is in the top menu.

Create performances with the "Record Performance" button in the top menu. These are saved as *.rpl files.
Use the "Export Performance as Movie" button to export as a movie or gif (separate tab).
The export doesn't need to finish for the time to count towards Coming to cinemas near you. Just start it, let it export a frame and cancel it. For example, if the performance is 5 minutes, start/abort the export process 12 times for the achievement.
Use the "Play Performance" button to play the *.rpl files locally. They loop automatically so this can be idled.

Only accepts *.avi files (who still uses them these days lol). Free samples can be found online. Use the "Load Video as Input Source" button in the top menu.

Add a *.kar karaoke file to the playlist in the "Karaoke Panel" (right menu) and play it for Wow, they still make those?. Free samples can be found online.
Set the playlist to repeat and let it run for 120 minutes for Superstar.