Best practices when you are Exporting your next 3D asset!
Optimize the file size
The file size of a 3D model should be relative to the complexity. The more complex the object is, the more triangles the 3D model has. A house with many large flat surfaces should have fewer triangles than a dog with many complicated shapes. A typical 3D file (glTF/glb) should be around 15 MB. Some are bigger; some are smaller.
Different pieces of an object are created separately. However, in the end, these objects are to be combined into one single 3D object.
Make sure that the UV map used in your 3D model is the correct scale and ratio. To ensure higher detail pieces have more resolution, you have to give them more UV space!
Textures are 2K (2048*2048) or less.
Textures are, in most cases, the cause of large 3D files. It would be best if you use a max of 2K textures in the Jpeg format. You should limit the number of textures used to five!
Export textures in JPEG whenever possible
MB's drastically increases if you use jpeg instead of png or TGA. You can change your textures in Photoshop by saving them as a 2048*2048 texture. The only reason for using a PNG is when your 3D model has some transparency, like glass.
The model is created on a real-world scale. This way, it should be the same size when placed next to the real-world object.
The model's pivot (center point) is positioned at the object's base and in its center.
Make sure that all objects are combined into objects. Also, freeze all transformations and, delete the history (Maya), apply all modifiers (blender)