R/E
Conjure Element, Double Shot
Method: Conjure Element, then Double Shot
Result: Two arrows at -25% damage (I.E. 150% over a regular shot), but both benefit from the extra elemental damage. This same strategy works with all Ranger preps.
R/W
Barbed Trap, Gash, Victory is Mine
Method: Lay a trap, when it goes off use Gash on somebody who's been affected. Then Victory is Mine.
Result: Bleed/Cripple on everyone in the trap's vicinity, Deep Wound on whoever took the Gash.. The three conditions feed Victory is Mine, and you regain all your Energy and some health to boot!
Me
Mind Wrack, Energy Burn, Energy Tap
Method: Cast Mind Wrack, then spam Energy Burn (or the Elite version, or both) and Tap (or the Elite version, or both).
Result: One round of Burn + Tap reduces the opponent's Energy by 12-22 (attributes depending), and does some damage (8 x 4 to 9, to be exact). Energy Tap also steals energy, which means you get some back. If their Energy reaches 0, they take Mind Wrack damage (40-75). If you want to be a real ass, you can Echo the Energy Burn. Unfortunately this doesn't do much damage for late-game purposes, but it can still rip an opponent's energy apart at no real cost to yourself, because you're stealing it back.
Me
Soothing Images, Ignorance, Energy Tap, Energy Burn
Method: Cast the above spells in order on a warrior or warrior-monk
Result: No adrenaline gain + No signets + No energy = No warrior