This thing is so cool and only recently I found about it. You can create pseudo fields with your entites, most often content types. So you can make some add, edit, delete buttons or any kind of forms on your entites or nodes. And it is pretty quick and straight fwd solution.

TO not need to use hook_entity_presave and save whole entity try this

//Get the id of your field
$field_name = 'name_of_your_field';
$info = field_info_field($field_name);
$fields = array($info['id']);

//Execute the storage function
field_sql_storage_field_storage_write($entity_type, $entity, 'update', $fields);

There is not much docs about this, but watching this video
https://www.youtube.com/watch?v=DJQnDZCbUHk
will help you with testing your drupal site and RESTful WS and Advanced REST Client.

You have error, your site is not accessable and you need to see what is the problem but logging and errors are set to none.
Type this with drush

drush vset error_level x

Where x is 0/1/2, depending on what you want

0: none
1: errors and warnings
2: all

You can also do the same with settings.php, adding to it this

I had a strange problem with Varnish, when users used form for longer period, like they inputed data and then submitted if it was 120 seconds or more, edit page would just refresh and nothing would be submitted.

When using different payment methods for checkout, sometimes you will have a payment gateway that will redirect you to different page, like paypal. But what if you want to have your frontender a chance to look at a page before redirect to style it?

My frotend guy asked me to put 3 columns of data per one row in views output so he can put zen grids over them. Not sure if he really needs that but I made it for him with a view template. Selected unformmated display style type, created template

We needed to have a custom page or a block to only change email and password on that page, and the other user info we separated in different page. Sounds like a nice solution for users. So what we did is the following.

-custom menu item
-custom form
-validation and submit

This one is short but sweet. Usually drupal forms don't have cancel buttons that bring you back to previous page, so lets add one.

The title says it all :) add this to your module, into hook_form_alter and rock