If you say something off the top of your head, you speak without giving too much thought to the accuracy or quality of your ideas. We use this expression when we want to say something on the spot, but when we are not certain that the information is entirely correct.
If you’ve stayed up all night, from dusk until dawn, then you’ve pulled an all-nighter. We use the term "all-nighter" to refer to an event that lasts through the night into the morning. This term is often associated with school and work, and it is used to say that a person stayed up all night to study for a test or complete a task.
If you have a project or task to do, and you have a very limited amount of time to finish it, then you can say that you're in a race against time.
When you learn the ropes, you learn how to do a particular task or activity. We use the expression learn the ropes when we are in the process of gathering basic knowledge and experience about how to perform a task or job.
When something bad happens, don't assume anyone did it on purpose. Instead, use Hanlon's razor to look for other reasons for people's behavior.
Use Occam's Razor to keep things simple when designing a business plan.
We generally prefer to discuss things we understand rather than things we don't, and that can be a big problem in interviews and meetings.