Many people use class based search, I have also mentioned it as one of the base strategy.
What I would suggest is after you done a thorough search in IPC and US classes you should also go for ECLA – European Classification.
You can search for your relevant ECLAs here
European Classification has been derived from IPC and is narrower than that. So the chances of digging into narrower domain are easier.
Benefit: Increased relevancy
Disadvantage: Search scope limited to European patents
Believe me it would be a beneficial strategy for you…
