1. Don't worry about writing yourself into a corner or having plot elements that don't make sense and you don't want to deal with later. Just throw in 'And it was all a dream' afterwards, it won't piss any of your readers off, and make them think it was a giant waste of time. Bonus points if it's the last sentence. Also make sure to say it WAS just a dream, and not them wondering if it was. It wasn't real, don't let them hope that it was.
2. One way to show that your character is likeable but kind of a doofus is to make it so they wake up to an alarm, and are automatically late to whatever. Because it's not you the author or the character having NO FUCKING CLUE how alarms work, they just go off late! Because SCIENCE!
3. Any fantasy world never changes. Not in 1,000 or even 5,000 years. People don't like experimenting, thinking, testing, trying ANYTHING. No one every wonders or progresses in much of anything. In fact, most times people actually get dumber, so most innovations are LOST FOREVER. This also helps to show how smart the protagonist is by having them come up with how things worked a thousand years ago, they must be a genius to figure out this lost way of doing things!
4. If you have a magic system, and have stated rules for the magic system, they only need to apply when it's good for the plot. When you need them to work a different way, don't bother having the characters need to think of a way around it, or giving them a bit of bother, just say the rules don't apply because MAGIC. In fact, "Because Magic" lets you fix any plot holes, rules-changing/breaking, and all sort of other stuff. Who cares about being consistent, or making your world-building make sense? The readers want the heroes to win with cool magic tricks!