Wraith King

If you have a strong level 2 powerspike on the lane, skill Vampiric Spirit on level 2, build up skeletons, release them on level 2 and use Wraithfire Blast.

Use Wraithfire Blast to secure ranged creep lasthits by either stunning the creep or an opponent.

When farming jungle, don't let your skeletons tank neutral creeps too much.

When neutral camp is at 30% of total health, move to the next camp to show your skeletons the way.

You should have vampiric spirit maxed out around level 7 to increase farming speed.

Consider keeping a skill point on level 6 or invest it in spells that will improve your farming speed if you are jungling.

Once you have a Blink Dagger, focus on killing backliners or supports first.

Mana burn is a big problem for the Wraith King. Consider aghanims shard when playing against heroes that have mana burn or buy diffusal.

Skeletons are not super useful in teamfights. Use them to push out lanes or after fights to take the buildings.

Wraith King has low armor. Pressure him with right clicks.

Reincarnation has a long cooldown on level 1. Look to pressure Wraith King while it is down.

Wraith King farms quickly with skeletons. Smoke on him, place deep wards and sentry off camps.

Don't use all your energy on Wraith King's first life unless you are sure you can kill him once more.

Mana burns are great at stopping Wraith King's Ulti until he gets Aghanim's Shard.

If wraith king seems to be saving gold he is most probably buying radiance, becareful of this timing and try punish this before he has it.