I'm not that experienced in gaming, but I have creating my own maps for quite awhile.  That is as fun as the creation of the scene. 

If I understand you right you are asking should you find brushes and paint the meshes after you render them?  I know there are people who do post work, but in making a game, that seems like a lot of work.  By exporting your figure as an OBJ and opening it in UV Mapper your usually get the template from which the creator of the figure used in creating his/her texture.  Take this into a paint program of your choice and go to town.  You will find all kinds of textures on line should you need them.  example, leather, cloth, metal, etc.  Using these will give a more realistic feel.  If you don't want to make your own template, then search for your meshs, texture file if it has one and use it as a template.  this site has a lot textures on it.  If your a member put them to use.   

If the mesh is your creation, then it is up to you to make a UV map for texturing.  Agan UVmapper is one of the ways to do this.

I hope this helps.