Creating a universe for your fantasy

I have just uploaded a fantasy "The Dragonskin Chronicles" Book 1 of 3 which follow the exploits of Korwyn, Lord of Man and Lady Zyndyr, Elf Warrior, as an example of how to build a believable fantasy world, in this case with the counterpoint of a modern world, so set up the conflicting thought of which world is the fantasy and which is real? 
 

Try and explain the fantasy world you've created, what the political and economic dynamics that explains context quickly and unobtrusively. Where is the logic behind every action? Try to describe each character so we know what they look like, visualise the scene and describe it. Give the reader some perspective: if your world is red, like Mars, then put in some descriptions, if it has strange creatures, describe them, ask yourself qur]estions and answer them, why do they exist in this form, are their actions and motives in keeping with the characters that you describe? What is the motivation behind their actions. Help ease the reader into the world you are making up, make them feel at home that this place could exist and the events could be real, so real that you want to be a part of it.