I have organized my entire friends list on Facebook. In the midst of categorizing each friend, I began to regret realizing how painstaking of a process it was to manage 441 friends into different groups. I wonder if FB users with over 500 friends will ever organize their lists as precisely as I did.
First, locate your Friends list under your Profile.
Click on Edit icon as shown above. You will be taken to the next screen similar to the following:
There is no ‘x’ next to Friends since that is your default Friends list. You can drag each list up and down to change the order of your lists.
Create new list
A modal window will pop up. On the first textbox, enter the name of the new list. Select friends to add to the new list. Click Create List after done selecting.
Add an existing list or group
You have two options:
1. Add Friends Lists
2. Add Groups
Friends lists are lists that you have created. Groups are Facebook groups, if you are a member of any. After done selecting lists and/or groups, click Add. I personally suggest adding only Friends Lists since Groups appear on the left panel of your Home screen.
—
Save Changes after you have completed categorizing your friends list.
Go to Profile and click on any of your Friends Lists. Notice the Edit Profile button on the top-right corner of your page changes to Edit Friends.
Click on Edit Friends.
You can click Create a List to create a new list. This is just another way to create a new list. On the left panel, notice that your friends lists are organized in alphabetical order.
Notice that Facebook has created a handy system list called Friends Not on a List below your lists. Click on a Friends list.
In case you missed a friend who belongs to an existing list or you have a new friend to add to an existing list, use this interface to add a single friend or multiple friends. Hover over a friend (near the left side of ‘x’) to view which lists the friend belongs to or add that friend to an existing list.
* Note that a friend can belong to multiple lists.
The downside
Now every time you make a new friend on FB you are forced to add him/her to a list, unless that person does not belong to any.
Friends Lists are not available on the Facebook Mobile App.
—
Organizing your friends is effective when you have countless friends and you want a quick overview of each Friends list. Sometimes, you may forget who are even on your Facebook Friends List or even their names.
Additionally, if you have sensitive friends, just create objective lists, no subjective lists. Frankly, I wanted to create a list called “Bros for Life”. Imagine the world of possibilities for psychological facebook effects this could have on you and your non-“Bros for Life” friends.
A Fool's Wish 
