We're starting to get an idea of what's on-topic. To summarize:
Non-standard solutions to physical problems** that use common objects.
Additionally, there is a general understanding that questions may not be psychological or medical.
Of the 37 non-duplicate closed questions, some are clearly not on-topic:
- https://lifehacks.stackexchange.com/questions/4054/are-there-any-uses-for-a-dead-computer-battery (Not a problem)
- https://lifehacks.stackexchange.com/questions/2565/how-to-maintain-a-to-do-list (Psychological)
- https://lifehacks.stackexchange.com/questions/4204/how-to-stop-receiving-commercial-spam-robocalls-to-my-phone (Not a physical problem)
- https://lifehacks.stackexchange.com/questions/4189/how-to-stop-cuts-scrapes-getting-infected (Medical)
- https://lifehacks.stackexchange.com/q/4037/15 (Not a problem)
However, there are others that are not as clear-cut:
- https://lifehacks.stackexchange.com/q/4129/15 (Ended up as a product recommendation)
- https://lifehacks.stackexchange.com/questions/4169/why-would-super-glue-gel-take-over-an-hour-to-harden (See this answer)
- https://lifehacks.stackexchange.com/questions/4233/how-do-i-use-my-smartphone-with-a-keyboard-and-mouse (No possible hackish solutions. The OP complained, as well.)
- How to avoid shortage of toilet paper? (The top-voted answer is the standard solution.)
- How to remove lice (All seven answers are product recommendations)
Alas! Our site is becoming inherently opinion-based!
How can we consistently decide whether or not a question is in need of closure, before it starts accumulating answers?