I catch myself (and others) writing phrases like the following:
I pushed on the door. Luckily it wasn’t locked.
Wary, she settled her weight on the roof tiles. At least they were dry—it hadn’t rained in weeks.
The first example isn’t very interesting, but because it’s so much simpler to analyze, I included it. The second example isn’t so bad, but could potentially stand to benefit from subtle changes.
These phrases are sidestepping storytelling issues. The first one, unless there’s a really believable reason why the character left it to chance if the door would be unlocked or not, it’s a plot device made of pure convenience for the author.
The second is an improvement because we see that the author thought about why walking on a roof might be dangerous, but it raises this risk of danger and then doesn’t deliver.
I think this stems from a thought that comes to the author in the moment of writing up a storm. The scene has momentum, there are other issues at hand, and so when that character steps onto the roof, she’s already got a job to do, and it isn’t to have a skating scene on a roof.
You can elevate character tension if you deny yourself any cheats. So long as it seems plausible that the character could deal with the added difficulty (even if it’s by the occasional stroke of dumb luck), and the difficulty isn’t just put there as a meaningless obstacle, you can raise the stakes on safety or reputation or whatever it is your character is risking.
In our second example, the author has demonstrated the value of forethought, but hasn’t raised the stakes. Sometimes this is fine. Not everything the character does needs to be the hardest feat the world has ever seen. But consider not giving your character an excuse for being able to perform the feat.
Maybe you should let it be slick, even unexpectedly so. Don’t launch into a 1000-word sub-scene of rooftop skating, but let us feel the added danger, even if it’s not the primary conflict.
On the other hand, you could enrich the scene by making it important earlier on that there has been no rain. It could be the reason why she thinks to try the roof in the first place, because she knows it’s not an insurmountable task.
Of course, if it makes no sense at all that your character just randomly breaks open a locked door with a previously unseen skill with lock picks, you shouldn’t go that route. Remember plausibility. Foreshadow. No miracle excuses to make a scene easier if you haven’t already justified it.
If you find yourself coming up with details and then mentioning them as things that aren’t transpiring, try flipping it on its head sometimes to make sure you’re keeping scenes unpredictable and lifelike.