Peek, Peak, and Pique : Grammar & Editing Tips

A few weeks ago, I posted about  Homophone and Contractions . Homophones are words that sound alike (can be spelled alike or not) but have different meanings. 
As an editor, I fix tons of homophones in manuscripts. From time to time, I thought I'd feature some commonly misused homophones. 
Today, I'll discuss peek, peak, and pique.
www.wigflip.comPeek
Think of the two Es as eyes. 
v. To look or glance furtivelyn. A quick or furtive look or glance
It's about a look or a look into something. 
I often see a mistake with "sneak peek"... I think it's because sneak has eak, so it's easy to mistakenly type peak instead of peek.

Peak

n. The pointed top of a mountain or range (or anything) / the maximum point, degree, or volume of anything
v. To reach the top

He reached the peak of the mountain race, which was the peak of his racing career.

Pique

Most commonly used in the phrase "pique someone's interest."

n. to affect with sharp irritation and resentment, especially by somewound to pride / to excite or arouse (interest, curiosity)
v. to arouse pique in someone

Is there an editing/grammar issue that's always caused you trouble? If so, share it in the comments so I can feature it in a future post. 
Definitions from Dictionary.com