Hardcode Stacks into theme2 users found helpful
In a nutshell, simply created a new stack with a helpful name, add blocks to it as necessary then, as shown on page linked above, simply stick this PHP into your theme where you want the stack to appear!
Eg. create new stack named 'Test Stack'. Add blocks and approve.
In your theme/templates:
$stack = Stack::getByName('Test Stack');
Please note, code above is for 5.5.1...code for 5.5.0 is slightly different, but is also detailed on Andrew's blog post.