Skip amritsar since it can extend your budget for sure. Travel Shimla & Chail (50km from Shimla), Manali, dalhousie Use himachal roadways for safe, comfort & good journey. Book hotels with good user rating on trip advisor.
Hi brother shimla would be great for your visit during December. You will enjoy the snow and breathtaking views of valleys.
But before you go pls book the hotels.
Do not stay in a hotel suggested by local agents who will catch you on bus stand and railway station.
if u want to stay in budget stay in dharamshala and spend the saved amount on shopping.
And pls do the horse riding at Kufri and toy train is must.