SharePoint Database growing very fast and need to be reduce the size??

Hi,

i am having problem with SharePoint DB, its growing very fast. Like Content DB, Search Crawl, Configuration DB, Usage Application and Reporting DB. So far i was able to reduce the Craw DB to shrink the database and assigned retention policy on Usage application by Get-SPUsageDefinition. i noticed some of my content DB is growing rapidly, same Content DB is showing different DB size (like site collection web analytics reports showing 41 GB but when i am checking db using powershell showing 62 GB for same Content DB). is there any way i can reduce the size with best practice?

Thanks in advanced!