ok - here's one but it relates to personal situation rather than business situation.
We have a radio boundary fence for our dogs. New dog arrived but we'd lost/misplaced the flags that visually mark the boundary for training. Rang around looking for said flags but sometimes could only buy with the full system.
Spouse then had the idea of using bamboo skewers with sections of white plastic cut from shopping bags. Easy peasy and no cost.
Thinking outside the box is really about looking at a problem, breaking it down, questioning assumptions and seeking alternatives.
on a business level - we also had a need for archival storage of docs and furniture etc. Looked into these self storage units as solution but pretty expensive on an ongoing basis. then realised there was space for a 20' steel container on-site - purchased second hand container - its ideal, does the job perfectly (airtight, dry) and the contents on site and accessible rather than in an industrial estate. Plus within 12 months had paid for itself (in comparison to self storage), no ongoing costs plus has a residual resale value should we wish to dispose of it.
Hope that helps.