Many requests are overlooked because they lack sufficient information on what is being requested.
When posting a new request, please keep in mind that the community does not know what you want if you do not describe it well enough.
Also, keep in mind that the community is no way obligated to help you, so a little respect goes a long way.
Don't demand that something be done - It most likely won't be.
With that said - The guidelines:
Besides everything described below, include a short description of what the asset will/may be used for.
A cool idea, or an idea which will be used in a cool project is more likely to attract attention!
When requesting 2D assets
Include an image size, color scheme and style in which you would like the asset to be made
Try to include at least some reference pictures, so that the artist has something to work with
Try to describe exactly what you want, in as much detail as possible
When requesting 3D assets
Include the target polycount, texture size, color scheme and style of the model
Include as many reference pictures as possible. General idea, shilouettes, detail pieces, materials etc.
Try to describe the asset in as much detail as you can
When requesting animations
Include the length and style of the animation
Try to provide a visual reference to the movements. Be it a video or a storyboard
Include the model which you want animated
Describe what you want in as much detail as possible
If applicable, include reference photos, videos or any other kind of material which may aid the artist in production
If you want help with something - Describe what you want to do, and what isn't working in as much detail as possible.
If you think it'll help, include screenshots or even a video of the problem so you can better give an idea of what you're doing and what's not working.
We don't know what you're doing and what's going wrong otherwise, so we can't help you.