Trudi Canavan — Australian Writer born on October 23, 1969,

Trudi Canavan is an Australian writer of fantasy novels, best known for her best-selling fantasy trilogies The Black Magician trilogy and Age of the Five. While establishing her writing career she worked as a graphic designer. She completed her third trilogy The Traitor Spy trilogy in August 2012 with The Traitor Queen. After this Canavan will be writing a new trilogy on a completely new world called Millennium’s Rule and will consist of multiple worlds which characters can cross between... (wikipedia)

Inspiration comes from so many sources. Music, other fiction, the non-fiction I read, TV shows, films, news reports, people I know, stories I hear, misheard words or lyrics, dreams... Motivation? The memory of the rush I get from a really good writing session - even on a bad day, I know I'll find that again if I keep going.
I always love writing the third book in a series because you get to tie up all the threads that you put out in the first two books. You finally let people know what really happens and reveal all the secrets and bring certain characters together.
I still recommend reading travel guides as an insight to a traveller's perspective on fantasy worlds. Nearly all characters end up travelling at some point, and they have many of the same needs and concerns covered in travel guides.
I don't have any specific plans to return to the 'Age of the Five.' If I do, it won't be a sequel.
The first rule of world-building is available physics, which basically means that if you want it to feel real, it has to follow the same rules as this world, from gravity to how human behaviour works. If you have a fantasy element that doesn't obey the laws of physics, make sure that it has a fantasy explanation.