The Glass Is Half FullAre your characters optimists or pessimists? This is an important question to ask for each character. It helps to set the tone for your world. Your voice or narrator can present things in wildly different ways. A line like "The flowers danced in the sunlight their scent reminding me of Spring" into a line like "I put sunglasses on to shield myself from the harsh rays of light, my sneezes remind me of the rampant infestation of pollen in the air". One casts a positive happy mood on things while the other sounds like something Grumpy Cat would say. Both lines could be used to describe the same thing.
Obviously the current situation will have an effect on how your characters feel at the time. Their outlook on life will still push things one way or another. Given a hopeless situation an optimistic voice will still cling to hope like a lost puppy. While a pessimistic voice will find something wrong with the least stressful of obstacles. The power of confidence and belief battles with doubt and denial all day every day. This is yet another layer that can be added to a character to make them feel realistic. Everyone has their inner doubts, but what side wins?
Set The MoodThis sets the tone for each scene, so think about what kind of scene it is. Are people going to die? Is it a jarring experience or are the heroes finally storming Captain Fluffything's evil fortress filled with death traps? That could help determine if you want to foreshadow what may happen by setting the mood going in. Even an optimistic character is not immune to the dark hue of the fact that something *might* happen.
As a writer you have the freedom to show readers that everything is not as rosy as it seems. It could be that the rose is made of glass and that glass is already cracking down the middle. All it would take is for the bad guys to touch it once and the whole thing would shatter. That would release the magic of the ancients and unlock the prison of the Undead Magna-Dragon. Then your heroes would have only 2 choices. Die while fighting valiantly, or unleash the Godzilla.
One of your characters may also have duct tape and think that will help hold the magic in. They can draw a smiley face in the middle of it as a ward against those who would try to run or say that we are all doomed. As a writer you can let that lighten the mood to act as a tension breaker or you could let the following silence hammer home the hopelessness of the situation.