Lee Sin is my main jungler. He is extremely flexible as he can be playe as a tank, a strong AD or something between the both.

When you are jungling, begin with your W and then use your other abilities as the shield will absorb some damage and it will give you attack speed.

Lee Sin is a very mobile champion and can use Wards to jump on and then kick someone into his team. So carrying wards or having a trinket ready is pretty good for Lee. He also teams up good with Midlaners like orianna and yasuo.