The following are some of the common methods of capturing leads:
Forms: Can be embedded on websites, ads, etc.
Phone calls: Incoming phone calls or voicemails can be captured as leads in a CRM
Emails: Incoming email inquiries can be added as a lead
List imports: lead information can be imported via spreadsheets
Data enrichment: Data enrichment tools fill-up the missing information of a lead through email or phone number provided