Here are a few pointers:
1) NEVER, EVER, HARDCAST YOUR LONGCAST SPELLS: Verthunder, Veraero, Scatter (becomes Impact @ lv. 66), and Verraise. Always use your Dualcast trait for these.
1a) there is an exception to this rule: If you ever enter a fight and the tank gives you a countdown (preferably 10 seconds or more) pop Acceleration at about 8 seconds. THE MOMENT you see the giant 5 for the countdown appear start hardcasting either Verthunder or Veraero then follow up with the other one. this will give you an instant "double proc". (See point 5 for double proc)
2) Take note that your shortcast spells: Jolt, Verfire, Verston, Vercure, Verthunder II (AOE), and Veraero II (AOE) all have a base cast time of 2.00 seconds. This means you only have to spend roughly 40% of your time in one place depending on how much your personal latency allows you to move around. Use this free time to reposition as needed.
3a) Embolden is weird in that it boosts YOUR magic attack and party members Physical Attack. Pay attention to your party makeup, especially if you have a basic understanding how the other classes play, to get the most of it.
3b) Manafication doubles your mana bars seperately, be careful their descrepancy is not too bad. If one is 16 points lower it will be 32 lower after manafication and, therefore, put you in an imbalance. Manafication mid sword combo WILL CANCEL the combo.
3c) Take note the timers on Embolden and Manafication are 120 seconds and 110 seconds respectively. This allows you some wiggle room to keep both buffs on similar cooldowns.
4) If acceleration comes off cooldown while I am mid-combo I prefer to use it 2 GCDs before my combo ends so it comes back up in my normal casting rotation faster while at the same time it wont fall off after getting the 3rd stack of it off. If you are working on your mana bars POP ACCELERATION OP COOLDOWN.
5) It is possible to get what RDM's call the "double proc". This is where BOTH Verfire and Verstone are ready to be casted as the same time. It usually happens due to the combo finisher activating the inactive one proc. Don't panic when this happens, just cast the one that is Lower then cast the element's longcast spell (i.e.: If you have the White magic bar lower cast Verstone -> Veraero. If you have the Black magic bar lower cast Verfire -> Verthunder)
6a) Corp-a-corps is not just for starting the melee combo, it does damage so use it on cooldown.
6b) Displacement is not just for starting the melee combo, it does damage so use it on cooldown.
6c) If using displacement will kill you then use Engagement (which we get at level 72). It shares the cooldown and has 50 less potency but you wont jump back to your death.
7) At Lv. 76 we get Reprise (which itself is a weak and useless melee ranges weaponskill). For the cost of 5 Black and 5 White mana it becomes a 300 potency ranged weaponskill. If you have 90/90 or better and have to wait a second to go in for your combo due to mechanics (i.e.: an AOE around the boss, tecker AOE's on the party members, or some other mechanic) pop a couple of these off until it is safe to go in or you can cast a few spell without capping the bar.
8a) Use Swiftcast whenever you can, AND CAST A LONGCAST spell with it.
8b) I like to use Lucid Dreaming whenever I have 7500 or less MP.
I hope these pointers are useful. Have fun with RDM and remember you are not the "Rez Dispenser" you are a DPS job.