I have a love-hate relationship with the writing life. I wouldn't wish to have any other kind of life... and on the other hand, I wish it were easier. It never is. The reward comes sentence by sentence. The reward comes in the unexpected inspiration. The reward comes from creating a character who lives and breathes and is perfectly real. But such effort it takes to attain the reward! I would never have believed it would take such effort.
Know what you love. Try imagining the book that would light your heart and mind on fire if you came across it in a bookstore - the one that would quicken your pulse and keep you up all night reading. What would it be? Details, details: when, where, what, who? Think it up, imagine it fully, then bring it forth. That's the book you should be writing.
It is my contention that a really great novel is made with a knife and not a pen. A novelist must have the intestinal fortitude to cut out even the most brilliant passage so long as it doesn't advance the story.