Tips to Use Bane (Dota2)

• Between levels 6-12 Bane is comparatively a very powerful hero, and assuming you maxed his Brain Sap (as you should under all circumstances) you will be able to solo most heroes by means of Fiend's Grip followed by Brain Sap. It is necessary to get kills during this phase of the game; as if Bane is not well-geared and leveled up later in the game, he will be relegated to a support unit.

• It is important for the player to judge when to change roles; as mentioned above, Bane should gank constantly in the middle of the game to gain a gold advantage and avoid getting shut down or subjugated to a conservative support role. A well-managed Bane can change the outcome of a team fight in the late game with effective use of items such as Necronomicon, Scythe of Vyse, and Aghanim's Scepter.

• New or unseasoned players have a tendency to attack targets under Nightmare. Before the game starts, make sure to warn them about it.

• Bane is not an initiator; despite having two disables, he is far too delicate to withstand the initial retaliation. Instead, he should hide until such time as his abilities become crucial when the team fight has ensued(preventing escapes, finishing off enemy heroes with Brain Sap, etc.).

• Avoid heroes with stuns, as they can interrupt Fiend's Grip. If you must deal with them, incapacitate them via Nightmare, a Scythe of Vyse, or Fiend's Grip itself. Picking Bane in a match against several heroes with disables is unwise. Black King Bar is typically an effective first major item to build on Bane if you need to help your team disable someone before they retaliate.

• If the enemy team lack area-of-effect stuns or interrupts, a Shadow Blade can make your ultimate harder to stop, since your opponents must first reveal you and then interrupt you. As with all similar abilities, you can activate invisibility without breaking your channel. While Shadow Blade is also effective for ganking solo heroes and escaping, you should still get Black King Bar instead if the enemy team have ranged AoE interrupts such as those possessed by Lina, Drow, Dark Seer, Death Prophet etcetera. 

source: http://dota2.gamepedia.com/Bane