"Ruffling one's feathers" is a common idiom used to describe a person who is annoyed or angry. However, if you are tired of using the same expression over and over again, here are some synonyms that you can use instead:
1. Getting under someone's skin
2. Pushing someone's buttons
3. Rubbing someone the wrong way
4. Making someone see red
5. Driving someone up the wall
6. Irritating someone to no end
7. Vexing someone
8. Miffing someone
9. Displeasing someone
10. Annoying someone to the point of frustration.
These synonyms can be used interchangeably with "ruffling one's feathers" to diversify the language used in your daily conversations or writings.