Need Advice & Help from Texture Artists!!!

Alright so I've been texturing for my models for a few months now but i can never get them to look realistic in Unity. I use Blender and Gimp,my process for creating textures is

1. After creating models i UV unwrap
2. Head into gimp and begin painting textures and such on the UV
3. Sometimes create additional textures for UV such as A.O(ambient occlusion)
4. save it then open unity and insert textures on models

Im about to texture the inside and outside of a house i need to...

Need Advice & Help from Texture Artists!!!