I think an important aspect is don't be afraid to change things on the fly. For example, if it's an insignificant fight and the players are being unlucky to the point that you should intervene then just lower the foes hits a bit... or... if they are walking through something you wanted to be more difficult, then have reinforcements arrive.
I also agree with this, and it has nothing to do with coddling the players.
To me the game is about having fun above all else. If a particular session is going bad for the players then I may change things around a little, make the enemy a little less challenging and so on. I usually don't fudge die rolls but I have and for good reason and again it has nothing to do with coddling the players, it has more to do with the story than anything.
What I mean by a bad session is when it seems all the important party rolls at critical moments tend to be fumbles which sucks for everyone including myself.
As a side note I tend to run long campaigns and certain characters become integral to the story at some point, for at least a little while. They all just made 7th level and we have been playing this game almost a year now and hopefully they will be done with part 1 by the end of January. Death is still possible and my players are very weary now. They tend to really take their time (sometimes to much time discussing and whatnot) then they need to, but they also blame that on me....lol. They know if they take chances in combat bad things happen (hey, crit happens). A few of them have been close to death a few times with one player loosing an arm below the elbow in one session and a leg in another. He had been healed appropriately both times, the bad thing is he is the healer in the group.
I use character backgrounds to help build the subplots and help further the story sometimes. It makes the players feel more involved than making a fighter or a mage and just taking part in the story, they become part of the story. FYI, character backgrounds are required in my games and sometimes getting a player to develop a decent background can be really difficult. But the payoff is well worth it.
Fate points are coveted in my games...lol. I recently added a deck of cards to the game where during travel times or when time passes by they can draw a card and certain cards mean they relate something about their background to the other players. This can be a good or bad memory, a love story, a tragedy, and so on. If by chance the players draw a joker they get a fate point, otherwise it is just extra experience.