To give your design consistency on every page select View/Master Page (Ctrl/M) and set up the column grid for the publication (the content of the master pages will underlie every page you choose to apply it to).
Click on the arrow on the right of the Master A tab and choose 'Layout Guides' from the menu.
Set up the guides as you require. As this is an A5 publication you should move the margins fairly close to the edge of the pages (1cm). In the first example the Grid Guides section has been used to set two equal columns:
We can make this design asymmetric by dragging the column guide to a new position:
The narrow column might be used for side headings and thumbnail images and the wide column for body text and large images.
With a single master page all pages will be the same.
To move the narrow margin to the right hand side of the right hand page we will have to create a second master page. To do this click the left hand button on the Master Page toolbar or click the New Master Page at the bottom of the Master Pages sidebar. Drag the column guides to the right side of the new master page. (It's a good idea to familiarise yourself with the Master Pages toolbar.)
To apply master pages to publication pages close Master Pages (Ctrl/M) and make sure you can see the Master Pages sidebar on the left of the screen.
To apply separate master pages to facing pages un-tick the option box and select the master pages you want from the drop-down lists.
To remove the effects of a master page click on the drop-down list for the master page and choose 'Ignore Master'.
You can create as many master pages as you like and apply them to the pages in your publication. For a complex magazine of, say, 100 or more pages, you may need a number of master pages for different sections or one-off pages; the master pages facility gives you the control you need over your layout and design. To use multiple masters create new Master Pages as before and apply them to the publication pages as required.
In the example below the Grid Guides section has been used to set two columns and 4 rows to help with page design.
Click OK to confirm settings. The central column divide can be dragged left or right to set up an asymmetric page design:
Another master page could be added to this design to allow the right hand page to be a mirror image rather than an exact copy.