Why we do not plan the itineraries...
Regarding your request. We do not create really itineraries, because it is really useless for us, most of the clients have no idea and to promise them Astronomical clock or Charles bridge does not make really sense as well because these are main stuff, which they can find easily without a guide.
Anyway in cases like yours we usually offer 2 four hour tours. One day one river side and the other day the other bank. So for one day I would suggest Left bank (Malá Strana - Lesser Town, and Prague Castle Area) and the other day Right one (Old, New and Jewish Town). The itinerary as well depends on if they want to visit the interiors too, or just walk around. We usually meet our guests in the hotel, explain them the history and the geography of the city, ask the , what they have already seen and what they would like to do that day (depending on their mood, weather and so).