Wow, Fronts finally clicked for me. Where once I struggled to create a second danger for a front I was able to quickly write four.
If you are having trouble writing a front take my advice: Stop and play the first session. Ask lots of questions of your players.
In my case a stole a map from http://rpgcharacters.wordpress.com/
and plunked my player's out front. I had some monsters I wanted to use planned and that was it. I asked my players for the mcguffin. "Why are you here?"
The answer was "we're here to retrieve a relic"
When they found the relic I asked them what it was: An evil crown that allows you to control people.
It was the paladin that came up with this and I suggested he make his quest move using finding the crown as his fiction. Now he has a quest to destroy the crown, although he doesn't know how that can be done.
End of session and I sit to write my Front. Front is destroying the crown and it's a campaign front.
Danger: The Order
The order that the paladin is a member of. They are misguided good and seek to keep the crown from corrupting. Anyone who comes into contact with it are potentially corrupted and a danger.
Danger: The Orcs of Ashara
A horde of Orcs who wish to recreate the kingdom of Ashara, the evil kingdom the crown built the last time it was unleashed upon the world. They have raiding parties looking for it and will soon be coming across the border en-mass in a war of conquest
Danger: The Blue Eyed Man
The blue eyed man is a mysterious collector of all things arcane and evil. He has agents seeking the crown and he will collect it by hook or by crook.
Danger: The Demon
The source of the crown's power. All suffering caused by the crown increases his power and prestige amongst the demons, to the point where he may be able to cross over into our world.
All this because I played my first session and asked lots of questions. Up to now I'd only played one-off dungeon crawls where I thought the dungeon would be my front. Doing it that way is hard. Making it fantastic is much easier.
I wrote a little more of it on my website: http://tyler.provick.ca/2013/10/16/dungeon-world-fronts/