Various stuff

Here are/will be various things which could help, but i cant or haven't created a proper tutorial for.
text in this colors are qc comments, like hints. you dont need to include them

   -Particles on a model
stuff for the particles... put below includemodel lines:

name celestia_hair // Particle effect's name within PCF
attachment_type follow_attachment // Tells particle to follow an $attachment
attachment_point sparkle_hair  // Particle effect will follow this $attachment

name celestia_tail
attachment_type follow_attachment
attachment_point sparkle_tail

//Attachment point is the $attachment the particle effect should follow and name is the name of the particle effect from whatever PCF

   -"I can't see textures on my model in HLMV"
There are several possible reasons:

1. Texture name in blender and vmt don't match.
2. Texture is not assigned to model, at all.
3. Vmt can't be found .
4. Vmt can't find the VTF file .
5. There's a typo in some texture name.
6. Wrong/missing $cdmaterials line in qc file.
7. You're using TF2s HLMV, use L4D2 HLMV.

   -"i released my mod on the workshop, but everyone says it's invisible"
There is only one reason and one way to fix it.

You used a custom name for the model during development or put it in a custom folder, because otherwise you are unable to see it in HLMV.

Then you renamed the model files and put it into the vpk file or took them with the correct name from the custom folder into the vpk file.

The fix:
When you're done with the whole model, change the $modelname line in the qc file to it's correct name and folder tree, then you compile it again and use those modelfiles in your vpk file.

HLMV always uses the models in the pak01_dir.vpk file if they are available, it will never use the model you put into the game folders. That's why you need to use a custom name in the first place.

Never rename the model files, because the mdl file itself contains information about the name and location of the model:

It will still work for you because the model you use in your vpk file still has the custom name/location information and that custom model is still in your game folders, so it will use that instead of the one in your vpk file.