If you are using Lightning the standard Salesforce Duplicate checking is quite OK.
Add the Duplicates Component on the top right hand side of the page, above Chatter.
Set only to Report if you can't deal with live duplicates happening - eg if you have Web to Lead and a Duplicate is found, the Web to Lead will report an error. So set Create to Report, not to Alert.
Duplicate rules interfere with Process Builder, you will get a Process Builder error rather than an alert about Duplicates, so set it to Report rather than Alert if you are using Process Builder on that object.
See also Making Sense of Duplicate Record Sets and Some notes about standard Duplicate Management.
Download the trial of Demand Tools (http://www.crmfusion.com/demandtools/), and then send CRM Fusion an email (nfp@crmfusion.com) asking to get the free NFP licensing for both Demand Tools and Dupe Blocker. (see http://www.crmfusion.com/nfp.php). You need to include your OrgID and your NFP confirmation (eg a copy of your DGR status or the ATO certificate is fine). |
However
Work as you are editing the record.
The duplicates to check for are particular to each organisation but here are some basics.