How to create master template in Qlik Sense

[arivqlik]

How to create the master template in Qlik. This template should defaulted for any sheet 

[dplr-rn]

What do you mean by template. If its just design elements you can use themes, backgourd image etc. at the app overview

[arivqlik]

When we create the new sheet, the new sheet should be defaulted custom
sheet which contains some images.

[ThePeterK]

This would be a very useful feature for "branding" apps without a lot of manual work. Are there any extensions that people have found, if this isn't out of the box functionality?

[Wlad_Masi]

Have you considered to use Themes? 
Please take a look at this Help Page.

A Mashup would be another good option, but it would envolve a little more work.