The best way to build a good relationship with Jian Wuxian is to give gifts. If you want to give gifts, you can click on "Send Gifts" to see what he likes, then focus on the + check bar lock position, and chase after giving.
I believe that after reading the guide brought to you, you will have a clear idea of the solution to this problem. So what are you waiting for? Come into the game and give it a try. As long as you don't miss any step, you can easily solve this problem.