Hi Thomas,
We would love to arrange a tour for you, here are some plans for your reference:
Plan A: 1 day in Tianjin, and 2 days to visit Beijing.
Here is a reference to you, but we would shorten your tour days.
6 days Beijing tour from Tianjin.
Plan B: 1 private in Tianjin, and 2 days group tour in Beijing. It will save you some money.
Plan C: 3 days private tour in Tianjin.
In Beijing, Best places to visit are Forbidden City, Temple of Heaven, Great Wall, Summer Palace, Beijing hutong, etc. Those places are worthy visiting, and highly recommended to you.
Any further request or question, please feel free to contact with us.