The "Tilt Shift" effect commonly known as the mockup effect is to add blur to photos in an elegant way.
Steps

Step 1. Go to Instagram
This is the application represented by an orange and pink icon with a white camera, on your home screen (iPhone / iPad) or in the application menu (Android).
- On the login page, enter your username and password and then press Log in.

Step 2. Press the New Post button
This is the button represented by a square icon with a sign +, found at the bottom center of the Instagram page.

Step 3. Select an image
Then tap Next. This button is located in the upper right corner of the screen.

Step 4. Tap Edit
This button is located at the bottom of the screen.

Step 5. Scroll right and select Tilt Shift
This is the penultimate edit option.

Step 6. Select a blur option
Choose one of the two options on the screen, and make your changes.
- Radial: this option allows you to add a blur effect to the corners of the photo, while leaving the central circular area of the photo sharp.
- Drag your finger across the photo to focus on the area of your choice.
- Using two fingers, use a pincer movement or vice versa to adjust the size of the blur effect.
- Linear: this option leaves a linear area of the photo sharp, and the other part blurry.
- Slide your finger across the photo to choose the sharp area.
- Pinch or reverse the photo to adjust the size of the blur effect.
- Tap and rotate your two fingers on the screen to rotate the linear area.

Step 7. Tap Done
This button is located at the bottom of the screen.

Step 8. Share your photo
Enter a caption in the text field, if you want, then press To share. Your photo will now appear in your Instagram feed.