A thing to remember here is that these posts are strictly meant for the particular planet position. Like, today we are looking at Moon in Gemini, so the description given here may change for you if your Moon is although in the sign of Gemini but with conjunction or aspected by other planets.

So, lets see what Moon can do in the sign of Gemini. 1st lets see what these 2 things represent -

Moon represents Mind, Emotions, Mother, Local Government, Peace of Mind, Home Environment, Water, Milk etc.

Gemini is the 3rd sign of zodiac belt, so it represents many things related with 3rd house of horoscope like, Communication Skills (either written, oral or even by sign language), Marketing, Business etc. It is a sign basically related with communications and business ideas. Gemini is divided into 2 and half nakshatra of Mrigashira, Ardra and Punarvasu. Gemini's lord is Mercury, which is significator of Communications.

So, here comes the natural entrepreneurs. When a person has Moon in Gemini, this person is always full of ideas and ideas are Business oriented 90% of times, because Gemini represents the 3rd house of Business. His mind is always running here and there. They can get into 10 different works and perform all of them with success. As Gemini is sign of communications, their mental balance is in intellectual communications with others. As they have so many business ideas, they would be better doing business rather than work under others. They can actually handle different businesses together. They can be very good in stock trading. They have lots of hobbies and creative skills. Communications become the most important part of life. As Moon represents Mother too, it shows either mother was also a business-lady or she was highly communicative with the native. As Mercury (lord of Gemini) represents young-age, these people are always very youthful, regardless of their age. 

Now, where does these things differ for different people born with Moon in Gemini. It depends on the Nakshtra Moon is placed in. So, if Moon is in Mrigshira Nakshatra, then we need to assess Moon's result through Mars position as Mrigshira is ruled by Mars. If Moon is in Ardra Nakshatra, then we need to assess Moon's result through Rahu's position as Ardra is ruled by Rahu. If Moon is in Punarvasu Nakshatra, then we need to assess Moon's result through Jupiter's position as Punarvasu is ruled by Jupiter.

Also, as Gemini is ruled by Mercury, we need to look at Mercury's position. Mercury's position will actually determine that how Moon is going to behave in Gemini. Again, horoscope should be judged in its totality.