1.
"The cheese is going to eat me!" Merlin screamed and snapped awake.

"I'm guessing it didn't work," Morgana said. It took him a moment to remember that the reason he'd woken up in Morgana's bed, with her framed against the window looking at him was that she'd been trying to teach him to dream prophetically.

"It might have worked," Merlin said defensively.

"Cheese?" Morgana arched an eyebrow.

"I had a traumatic experience with a butter churn as a child."

"Somehow, that doesn't surprise me. Why don't you go home and leave the dreaming to me?"

2.
Scrying was harder than Merlin had been expecting.

"What can you see?" Morgana asked.

Merlin peered into the basin of water. "I see, it's, it looks like- Hang on, no, sorry, it's a crack in the bottom of the basin. I don't think you can see anything either."

Morgana looked down into the water and smirked knowingly. "Watch out for the third head, won't you? Those teeth look like they might be poisonous."

3.
Merlin had been trying to get the hang of turning water into wine for ages. Morgana had picked it up like that, Merlin tried to snap his fingers to demonstrate the length of time 'like that' was, unfortunately the effort involved in resulted in Merlin setting fire to his neckerchief and falling out of his chair.

Morgana looked down at him, perhaps she needed to pay more attention to the strength of the wine. "Come on, Merlin, up you get." Morgana decided to deposit him in Arthur's chambers

4.
The first clue Merlin got that magic was outlawed in Mercia was when he and Morgana were seized and thrown in prison. Luckily, it wasn't long before Morgana got the key from the guard and broke them out.

"Can you teach me that spell?" Merlin asked, as they crept to the stables to liberate two horses.

"Of course," Morgana said, smiling at the image of Merlin asking the guard for just one kiss the next time he and Arthur got locked away somewhere. After all, female wiles and skilled pickpocketing look almost like sorcery in the right light.

5.
In the end Uther didn't have Merlin and Morgana executed for using magic in Mercia because he didn't remember that they went to Mercia in the first place. Gaius would certainly disapprove of using magic to remove the King's memories, and Merlin isn't sure how he feels about Morgana having the ability to alter peoples minds like that. But it did save both of their lives, and the fact that it made Uther so woozy that he nearly fell out of his throne was pretty funny, too.