apply oneself
To try hard or concentrate one's abilities (toward something). Without the preposition "to," it refers to a concentrated effort in general. I know you think you won't be able to understand this level of math, but you just need to apply yourself, and you'll find success. If we apply ourselves to the problem, we'll find a solution eventually.
find it in (oneself) (to do something)
To have the courage, conviction, or compassion to do or go through with something. If you could find it in yourself to lend me a few hundred bucks, it would really get me out of a jam. I simply couldn't find it in myself to fire him after he had just found out his father had passed away.
find (oneself)
1. To discover and pursue one's true and inherent character, passion, skill, or vocation. I know you're unhappy in your job, so I think you should take some time off to really find yourself. Many students leave college and realize that they still have yet to find themselves.
2. To discover, recognize, or realize one's location, thoughts, or sentiments. Lost in a deep reverie, I suddenly found myself in a neighborhood I didn't recognize. I find myself inclined to agree with the professor's assessment.
flatter (oneself)
To hold a vain, self-congratulatory, and exaggeratedly high opinion of oneself and/or one's achievements. Yeah, don't flatter yourself—she only asked you out to dinner because she wants to ask you about your brother. Gaston likes to flatter himself that he's the best man in town, but everyone knows he's just a pompous jerk.
go hang yourself
Used as a rude imperative to indicate one's disapproval, apathy, or disdain regarding someone's words, thoughts, or actions. If you really think it's your prerogative to tell me how to run my business, then you can go hang yourself for all I care. She can go hang herself if she thinks I'm going to come into work on a Saturday.
help (oneself) (to something)
To serve oneself (something); to take, consume, or indulge in (something) freely or without permission or restraint. There's plenty of food in the kitchen, so please, help yourselves to more. The vagrant they had given shelter to for the night helped himself to the family's prized set of silverware. The maps at the information kiosk are free, so tourists are welcome to help themselves.
bear (one)self
To behave in a particular way. I need to bear myself bravely if I want to overcome this fear. I know you guys aren't thrilled about going to Great-Aunt Mildred's, but please try to bear yourselves politely.