Below are a few key points to note when check documents. Note, this process should only take 1-2 minutes assuming they have brought the necessary documents.

Original documents only, no photocopies/scans/printouts
Has to be presented by applicant themselves, not a 3rd party
Check pictures on ID documents are those of the applicant
Check names on official government issued documents are identical. The system will reject entry of these documents if one has a middle name and another does not for example.
Check Addresses match on all documents
Check Date of Birth matches on all documents
Check dates on document are full dates (day, month & year) and within the timeframes required (either current and valid, 12 months or 3 months dependent on document type)
When you take a picture of the ID to enter on system later, make sure you can read all the information in the picture before giving back the document
Assure them that pictures of the documents taken will be deleted immediately on successfully entered onto the DBS system.
Update the DBS Expiry field on applicant's Pitchero record to show that they are in the process of applying. Add text '***ID received on 1 Oct 2019' where dat would be when ID was checked.