Drupal Drug

Use 'elseif' instead of 'else if'
#CodingTips

As of PHP 5.4 you can also use the short array syntax, which replaces array() with []
#CodingTips

Functions in general shall be named using snake_case(say, my_function()), and using camelCase(say, myFunction()) when declared within a plugin class
#CodingTips

Variables in general shall be named using snake_case(say, $my_variable), and using camelCase(say, $myVariable) when declared within a plugin class
#CodingTips

Manage automatically assigning of new permissions whenever a module is enabled here- admin/config/people/accounts
#ConfigurationTips

Manage source of Main-menu and User-menu links here- admin/structure/menu/settings
#ConfigurationTips

Helper function(s) shall be named prefixing an underscore(say, _my_helper_function()), which can prevent hooks from being called
#CodingTips

Ideally, configuring of 'Private file system path' at admin/config/media/file-system should be located outside of your Drupal root folder(say, ../my_private_files)
#ConfigurationTips

You should be aware that uploading files as 'Private file' will slow down the process of loading the files as Drupal has to be bootstrapped for every file that needs to be downloaded
#ConfigurationTips #BeAware

Code should always be pushed up(dev -> staging -> production) and databases should only be pushed down(production -> staging -> dev)
#DevelopmentTips

Get Raw SQL Query of drupal dynamic queries before executing it using $query->__toString();
#DebugTips

In VI-Editor, Press ESC key to come in command mode and for undo type :U and for redo type :Ctrl+R
#LinuxTips

Insert queries must always use a query builder object(layer of abstraction), allowing individual database drivers special handling for column values (if applicable), example case for LOB and BLOB fields.
#DatabaseQueryTips

Drupal uses the .inc extension to prevent files from being executed directly.
#DevelopmentTips