Pros:
- Clears jungle fast
- Strong ganks which rarely fail if done correctly
- Very Strong late game
- Excellent at focusing specific targets in team fights with Ult as it brings attention to the rest of the team.

Cons
- Weaker early game
- Must start blue
- Easily counter jungled (VS a skilled counter jungler)
- Mana heavy user

Flash is good for multiple reasons but I would also recommend trying Ghost with Skarner. It has many utility uses for ganking and peeling.

Have a teammate ward your red buff as Skarner is susceptible to being counter jungled.

Always start at blue. I've tried red and it works against skarner as he uses abilities quite frequently.

Clear Wolves second and then clear Wraiths third.

Check the surrounding bushes of your red buff. 75% of my games as Skarner have resulted in an attempt of the enemy jungler trying to steal red buff after killing me. If you are premade with someone in a near lane let them know that they may have to assist you. I would recommend placing a ward through the wall behind the red buff into the bush and check the surrounding bushes before proceeding to clear the red buff.

DO NOT use your E to farm your jungle. Strictly use it on enemy champions or slowing minion waves.

Ganks at level 6 rarely fail if the laner is aware but for ganks before level 6, you must have at least 1 point in your E for the extra crowd control.