I write a lot of fantasy and science-fiction based stuff (often with elements of horror). I enjoy dealing with exotic settings, alien cultures and mindsets, and strange powers. Just about the only sort of power I don't regularly play with is... how to say this? ...anything involving Time. Traveling through time, manipulating time... the thing is, time is so fundamental, so essential to the way people look at the world, that any time it appears in the story it's going to require an awful lot of attention and some very careful handling. This brings me to the following rule of thumb:
Don't include time-based powers unless they're the focus of your story.
Because otherwise... well, let me demonstrate the sort of thing that happens if you haven't thought your time-based powers through very carefully. This actually happened in a roleplaying game, though it was years ago and I'm probably misremembering some of the details:
The battle had been long and the fighting fierce, but the outcome was no longer in doubt. Our enemy had underestimated our strengths, and the men and beasts that served him had fallen by the dozens. To my right, Adiam released his prepared spells, blasting and battering his targets; to my right, Nadrick's twin sabers carved a line through the enemy ranks. I had taken a new form especially for this battle, immensely strong and nearly invulnerable; what my claws couldn't pierce, I broke or hurled aside.
The enemy fell back, formations collapsing as they gathered to protect their master. They were too far beneath his control to ever consider flight; they would fight to the last to protect him. Yet few enough of them remained, and those were not sufficient to hold us back. We could see our target, standing on a slight rise at their center; a position chosen so that he could survey the fighting and loose spells of his own. Now the unmistakable sight of defeat greeted his eyes; if he would turn the course of battle, he must do it soon.
From across the field, I saw him draw something from his belt and raise it over his head: a scroll, or something like it. A scrap of parchment, perhaps. A gust of wind tugged at his robes, then fell still. "You will not take me!" he cried, and his voice rolled across the field like the sound of a great bell. "I have a one-way ticket to midnight!"
Saying this, he tore the parchment in half. Power rolled out from where he stood, its weight unmistakable though we could see only its effects: our enemy and all his warrior-slaves were gone. The sounds of fighting were absent; only the cries of the wounded and dying filled the afternoon air. Nadrick, with a speed I could never hope to match, had hurled one of his sabers. It spun across the empty hilltop and fell to the ground somewhere beyond. Adiam stood startled, the guide words for his next bit of destruction ready on his lips.
For a moment, we all looked at each other. Adiam spoke bitterly: "The fiend has escaped us."
"Perhaps," I said, and they both turned to look at me. "Did he not say, 'midnight'?"
Adiam nodded slowly. Nadrick started to grin.
"It lacks an hour or so of sunset," I said. My voice was a throaty growl in this form, but it couldn't be helped. Until we'd checked the wounded, I wouldn't resume a human configuration. "That gives us, what? Five or six hours to prepare, if he will reappear here." We all considered that. "We can eat, and rest, and be fresh when he arrives battle-weary."
"...And lay traps," said Adiam. I could see his mind spinning as he considered the possibilities. He, too, was smiling now.
"He'll be dead before he realizes his mistake," said Nadrick.
...Which was about the point where the Gamemaster called a sudden and panicked halt. Apparently the "one-way ticket to midnight" had been a staple of his former gaming group, a way that bad guys (and eventually the players) could absolutely and irrevocably escape from danger. But all it actually did was project them forward through time; they would reappear in the same place, except at midnight. And that meant that those of us who were "left behind" in the normal flow of time could reach the same place, just by waiting... and the escape that appeared to happen instantly for those who used the Ticket would give us several hours while we made the same passage though time in the more ordinary way.
Time-based powers are messy. They don't balance well with other powers; either they're an absolute and nearly-unbeatable advantage, or they're very nearly useless. To make them work at all requires far more attention than they're usually worth - unless, of course, time and/or time travel are the focus of the story, in which case you're balancing them against other time-based powers.