The scope is defined by the questions that are welcome. That leaves us with the definition of on-topic-question:
- You need to have a specific problem. You, not anyone else, not an idea you have that could be a problem. It needs to be specific and you need to state your very problem in your question. SE is best at solving actual problems, don't skip that part.
- It needs to be a physical problem. Something that you can grab with your hand.
- You need to seek solutions that can be applied quickly and/or cheaply.
- No questions about your body functions and / or medical advice.
After that apply the content of this Meta to improve your question from "okay" to "high quality"
Please note that nothing in this post tries to define what a lifehack is. Because thats for the answers and the scope is defined by questions, not answers.
As a sidenote: I felt that the scope was well understood in the last days. When I opened the front page I mostly saw questions I would expect.