Spelling
Provide a transparent correction when the term is likely.
Zero-result searches
An empty result does not have to be a dead end.
Explain what happened and provide routes that fit the likely cause of the empty search.
Alternative query
Prese a broader or related term without hiding the original intention.
Categories
Use categories when the query is wide or orientation.
Assortment
Make it clear when something is not supposedly not sold.
Contact
For B2B or complex products, human help can be a useful fallback.
Measuring
Track which recovery route still leads to click or conversion.