Add a Jquery ui library

get the library names to use in /misc/ui folder

  1. drupal_add_library('system', 'ui.slider');

The easing effects are shipped in the effects.bounce library

  1. drupal_add_library('system', 'effects.bounce');

easing effects demo http://jqueryui.com/effect/#easing

Display errors - WSOD

The bootstrap override the values you could set to display error ad the reporting level. To be 100% sure everything is printed out when something fails in a blank screen (wsod), make index.php like this:

Properly render a field

Drupal offers a few (sometimes complicated...) solutions to output a field. Lets take an example with a date field.
To display the full rendered field: field_view_field()

Using once()

ensure ajax reload don't apply the behaviours for items already processed

Change the theme

Programmatically change the theme on runtime by implementing hook_custom_theme()

Manually clear caches

for views and panels

Add a Jquery ui library

get the library names to use in /misc/ui folder

Embed a custom page

Get the rendered output of a custom page created with page manager (ctools) module

Embed a mini panel

Get the html output of a mini-panel

alter / automatize the install process

in the .profile file of the install profile (here "mysnippet" profile)

Aegir: perform custom tasks after a new site is installed

in a custom module, in a file called mysnippet.drush.inc (keep in mind that the install process is handled by drush...)