I wish to make use of a template override for Articles in Joomla, well, i am using

mytemplate/html/com_content/article/default.php

Basically change anything within this file the alterations do appear. But as I wish to make use of an extra .php-file f.e.

mytemplate/html/com_content/article/alternativeLayout.php 

I'm facing an issue. Because although I'm able to choose this layout around the article configurations page - any Changes I get by not appear but still the default.php can be used.

Any ideas things i am doing wrong?

To ensure that an alternate layout for use, two conditions should be met -

  1. You have to choose design within the article parameters
  2. No food selection can exists for this item - design choice of recption menus item will override the choice within the article parameters

It may sound much like your issue is with #2.

EDIT Duh, I skipped the important thing a part of using alternate designs. To be able to have the ability to make use of an alternate layout having a food selection, you need to create an alternatelayout.xml file and put it within the override folder. This provides you with one more food selection option that you simply choose when designing your food selection. You need to have the ability to copy the defailt.xml file and edit it for that new layout.