In Shi'ite Islam Qiyaas (making analogy) is forbidden, and instead Aghl (intellect) is substituted and also Ahadith are also provided from all the 14 infallibles A.S., as already stated by the other members.
Note that Qiyaas and Aghl are both devolved to Muslims not being infallible. These are required as to find the answer for new questions in different times (so that Islam is alive), and on the hand should be used only with ultimate care not to let personal ideas enter the Ash-Shari'ah.
According to Shia Islam Aghl is permitted to be used as Quran declares that for example after stating a rule:
كَذَٰلِكَ يُبَيِّنُ ٱللَّهُ لَكُمْ ءَايَـٰتِهِۦ لَعَلَّكُمْ
Thus doth Allah Make clear His Signs to you: In order that ye may
Or after complaining those who do not use their intellect about what rule is the rule of Allah and what is not, invented as a lie against Allah:
مَا جَعَلَ ٱللَّهُ مِنۢ بَحِيرَةٍۢ وَلَا سَآئِبَةٍۢ وَلَا وَصِيلَةٍۢ
وَلَا حَامٍۢ ۙ وَلَـٰكِنَّ ٱلَّذِينَ كَفَرُوا۟ يَفْتَرُونَ عَلَى
ٱللَّهِ ٱلْكَذِبَ ۖ وَأَكْثَرُهُمْ لَا يَعْقِلُونَ
It was not Allah who instituted (superstitions like those of) a
slit-ear she-camel, or a she-camel let loose for free pasture, or idol
sacrifices for twin-births in animals, or stallion-camels freed from
work: It is blasphemers who invent a lie against Allah; but most of
them lack wisdom. (Al-Maa'edeh:103)
And also there is famous Hadith in Shia Islam that everything commanded by Aghl (not personal feelings) is also approved by Shar' and everything commanded by Shar' is also approved by Aghl (کلما امر به العقل امر به الشرع، و کلما امر به الشرع امر به العقل).
However, there are evidences that Qiyaas is not permitted in Islam, e.g., once there was a debate between Imam Sadiq AS and one of the Sunni Imams, Imam Sadiq AS asked him if he exploit Qiyas and he answered yes, then Imam A.S. Asked him three questions in this regard one of them is this: Which sin is bigger, murder or adultery (Zinaa')? He answered back Murder. Imam AS asked him then why does Allah states in his book that proof of murder needs 2 witnesses whereas the proof of adultery needs 4 person as witness? Not all the underlying wisdoms of a rule is clear to us so that Qiyaas (making analogy between different rules) is forbidden in Shia Islam.
The rest of sources of legislation is common in Shi'ite and Sunnah, except for them having different authentic Ahadith, as you already know.