Probably the easiest way to create a slideshow with Flex Slider is by using the "Flex Slider Fields" module, as it doesn't use Views at all. This video shows how to create slideshows from basic multi-value image fields.

Image Field Slideshow

Enable

• Flex Slider Fields

This module simply works by configuring the display settings for any content type that has a multi-value image field. Let's add a multiple-value image field to our Basic Page content type.

• Go to "Structure => Content types => Basic page => Manage fields" (admin/structure/types/manage/page/fields)
• Add new field
  • Label: Photos
  • Type: Image
  • Number of values: Unlimited

Create a Basic Page

• Go to "Content => Add content => Basic page" (node/add/page)
• Title: Test Page
• Body: (Dummy Lorem ipsum)
• Photos: (Upload a few photos)

When we save the page, we'll see all of the photos we just added. Now, let's manage the display, and tell Flex Slider to display our images in a slideshow.

Manage display

• Go to "Structure => Content types => Basic page => Manage display" (admin/structure/types/manage/page/display)
• Photos
  • Label: Hidden
  • Format: flexslider
  • Option set: Default (Click the gear icon to choose between the option set's you've created)

Now, when we go back and view our page, the images are displayed in a slideshow using Flex Slider.