I don't know if you want to include useful "Tips for best use" sorts of things, but it might be nice to mention that if you are a DD in a party (can be done solo but more difficult, and the tank shouldn't shift too much for risk of disrupting other members' positions) you should use all of your combos, even the "less powerful" ones. The reason is simply this: each combo weapon skill is free damage.

Using LNC as an example, the third tier weaponskills - Doomspike and Chaos Thrust - have 60s and 80s cooldowns respectively. Once reaching 1000-1500 TP, if you chain True Thrust -> Leg Sweep -> Doomspike with an Auto-attack in between each attack, you will end the combo with about the same TP as you start and, more importantly, it will take approximately 30 seconds to complete. Immediately jumping into Vorpal Thrust -> Impulse Drive -> Chaos Thrust using the same timing will drop you off at the top of the list right about when Doomspike's recast runs out.

The technique can be extrapolated to any class, and while some probably consider this to be blatantly obvious, I'm sure others will appreciate the suggestion.