For solo play (or maybe with simular geared multibox setup, especially haste) it's probably best to go by a priority casting rotation. Lava Burst is currently by far your biggest nuke and should definitly be used in your rotation.

If you don't glyph Flame Shock you could probably make a static rotation, but you'll loose dps for not glyphing it (but static rotations are easier to box). You could go with Glyph of Lava, Lightning Bolt (or maybe CL) and Flametongue for this. Depending on haste you'll end up with something like Flame Shock, Lava Burst, LB, CL, LB, LB.

For best dps you will want to go by a priority rotation. Glyphs: Flame shock, Lava and Flametongue (of Lightning Bolt if you have mana problems now, always from 3.08). What you do is just make sure Flame Shock is always on your target before you cast Lava Burst, then prioritise Lava Burst -> Chain Lightning depending on c/d, fill with LB. This isn't easy to not mess up if you have high latency or with the lag the servers (or at least mine) has been having lately, so probably not the easiest to box.