Plan to go to Lijiang and Dali.

During the 3 days, you can go to visit Yunnan Stone Forest, Dianchi Lake, Golden Temple, Western Hills and Grand View Park. One day may be short for visiting Lijiang or Dali. Both of the 2 cities are worth visiting. I suggest you spend at least 2 days in each city. If you only have 5 days, you can spend 2 days in Kunming, 2 days in Lijiang and 1 day for a short visit in Dali. It may be a rush journey.