Apart from using forms for data collection, you can also create dynamic forms, populated from data in your Salesforce Org or from URL parameters constructed from an email template (for example).

Dynamic pre-fill will pre-populate Child and Parent related objects and you can add custom filters as to which child objects to display.

So, you can create Contracts, auto-populated with contact details or complex Expense Forms to collect worker’s expenses. The key is pre-appending a record to the form, so that the final form is personal and linked to the correct record in Salesforce.