I just went on a 15-day trip to Taiwan. The main purpose of the trip is to attend the Countdown party at Taipei. So during our planning, we must make sure we are in Taipei on 31st Dec. For the places we want to visit, most travellers will usually plan to travel in a loop: Taipei > Miaoli > Taichung > Kaohsiung > Guanziling > Alishan > Sun Moon Lake > Qing Jing > Ao Wan Da > Hualien > Yilan > Taipei.
However, to make sure we are back in Taipei on the 31st, our itinerary is as follows: Taipei > Kaoshiung > Guanziling > Alishan > Sun Moon Lake > Qing Jing > Ao Wan Da > Taipei > Miaoli > Taipei > Yilan > Huanlien > Taichung > Taipei.
Hope that the itinerary will be helpful to those who are planning to go Taiwan.