Never buy stat items on the Bear, raw damage and attack speed items work but agility and strength do not apply to summons.

Put Phase Boots, Mask of Madness and Desolator on the Bear, then solo Roshan around 15 to 18 minutes.

Use both units' Savage Roar, you get two charges of fear that chain enemies for nearly five seconds.

Split push by sending the Bear to one lane in True Form while the hero farms another with no leash limit.

Keep the Bear alive at all costs, it has a 120 second cooldown when it dies and you lose most of your damage.

Protect the Bear with BKB before committing it in teamfights, a disabled Bear is a wasted hero.