Again, I discusss this in more detail in creating the modern romance epic . Basically, not very different at all. Readers don't want the gap to be very wide at all, they want to be able to step across the instant they take up the book. The most successful fantasy books are those where the fantasy world is our world in all but name. It's often been pointed out that fantasy books can foster racism, simply because of the stark contrast between the good races and the bad races, where the bad races are always unredeemable. be paternalistic and sexist, esp with treatment of female characters.
Modern publishers are desperate for books with strong female characters, as are the public.
Don't just have your female characters be gorgeous princesses on the side who weep and wail and wait for the golden hero to save them. It is a fine line to tread and you must be careful. Too many authors try to be like Tolkien, but the market, as publishers, basically don't want another Tolkien-imitation. Use it, but be original with it. Creating the fantasy world.