I understand lots of people use backgrounds in their GFX, which is rendered but how do I achieve this, because whenever I try a background it does not turn out great and I keep wondering if there is some sort of way to make them blend and look clean.
As you can see in this image, I want to know how to do the sky and the trees background.
Thank you for reading! 
What I would do is that I will export it (the trees) from studio then import it in blender together with some other stuff that I would like to add to the background then for the sky, I will just search for a gloomy sky background on google that looks similar to that then put it behind my render then edit the hue, saturation, brightness, etc.
This might not work for you but that’s what I would do.
Alright, thank you! I will try that.
Either you would do what @GirlSwag911 said or either you would get a forest backround change the textures In ohotoshop so it matches the roblox character. Thats a bit harder I reccomend doing what @GirlSwag911 said.
You can use a HDRI for it. Here’s a tutorial on how to use it if you need it: https://www.youtube.com/watch?v=6VBkj_I-ONk