From Delhi.....

(1...) Agra 01 Nights / 02 Days
Day1 Transfer to railway station to depart Delhi by train. On arrival at Agra transfer to the hotel. Visit Agra Fort and Taj Mahal. Evening local dances. Overnight at hotel.
Day2 See Fatehpur Sikri - the deserted capital built by Akbar the great who later shifted the capital to Agra for want of water. Afternoon see Sikandra, the mausoleum of Akbar and transfer to railway station for train to Delhi. On arrival, transfer to international airport for flight to onward destination.

(2...) Shimla 03 Nights / 04 Days
Day1 Morning transfer to railway station to board Himalayan Queen for Kalka and then proceed by narrow gauge rail car to Shimla. One can even drive from Kalka to Shimla also.
Day2&3 In Shimla at leisure and free for independent activities. Shimla used to be summer capital during the British period. At an altitude of 2130 metres, Shimla sprawls along a crescent-shaped ridge with its suburbs clinging to the slops.
Day4 Drive from Shimla to Kalka and then transfer to railway station to catch the overnight train to Delhi. On arrival, transfer to international airport for flight to onward destination.

(3...) Corbett Park 03 Nights / 04 Days
Day1 Drive from Delhi to Corbett (295 kms/6 hrs & 30 mins). Check into the hotel. Overnight at Corbett.
Day2 Enjoy viewing the wildlife on elephant back. Overnight at Corbett.
Day3 Enjoy viewing the wildlife by jeep safari. Overnight at Corbett.
Day4 After breakfast drive back to Delhi. On arrival, transfer to international airport for flight to onward destination

You have been to all the popular (read crowded) hill stations. This time you just feel like going to some remote village in hills and spend a few days with local tribal people there, and relish local delicacies. You are a writer and an ardent nature lover. Spending a few days closer to nature not only rejuvenates you, but also gives you a lot of inspiration in your chosen field. You are a busy executive working day and night. You desperately need a break where there is nobody except you and your family. You just like to laze around on a golden beach. You want to go to a popular tourist destination, but stay away from the entire hustle bustle. You want your holiday to be informative & educative for your children. You want to combine holiday with pilgrimage.