To preview any/all form templates that have been shared with you visit templates, my templates. Click on the drop down in the upper right hand corner and select Shared with Me.
Any template shared with you is a template that you can engage a client with. Depending on the settings that the original owner of the shared template has set you'll be able to view what can be done with the template by clicking on it and looking at the template details toolbar at the top. Anything greyed out is unavailable for you to do with this template.
To share a form template.
Visit Templates > My Templates (under form Templates) > click the Share button.
You can then choose to share the template, allow copies of the template to be made and to share it with everyone or configure to share with a specific team.