Warden

Easy Quickslot Arrangement for Remembering Gambits:

In the quickslot grid below there are 11 gambit categories. 8 are set up horizontally, and 3 are set up vertically.
You start clicking from left to right or top to bottom, and the farther you go the stronger the gambit becomes.

As you play you will get familiar with which line to follow for different effects.

Later in the game, you can equip traits which allow you to perform a 2-letter combo with just the click of one button. If you want to use these, just replace the first two letters of each row with a 2-letter icon.

This is the best way to place the 2-letter icons, because placing them there:

1. will not disrupt the vertical gambits.
2. will allow enough time for them to cool down between gambits (they have a longish cool down).
3. will allow you the flexibility to perform any length gambit whereas if you placed two in a row you would not be able to perform a 3-length gambit of that category. You want to be able to perform all different lengths because the buffs and effects of a gambit don't really stack on themselves.
   

This is a great thread containing links to many different gambit charts (but no quickslot suggestions): http://community.codemasters.com/forum/warden-1159/329699-gambits-made-easy.html#post4820265

Of those charts, here are my two favorites:
http://mkweb.bcgsc.ca/lotro/
http://files1.guildlaunch.net/guild/library/16828/Gambit-by-effect.pdf