To Perform Rituals without Taqlīd

The actions of a person who does not follow a mujtahid are valid provided that they are in accordance with caution, the actual rule, or the fatwā of the mujtahid to whom they must refer.

A Blameworthy/Unblameworthy Ignorant

A"blameworthy ignorant person" is the one who realizes his ignorance and knows the possible methods by which he can overcome his ignorance, but deals carelessly with learning religious rulings. An "unblameworhty ignorant person is the one  who is not at all aware of his ignorance or he/she is aware of it, but there is no way out of it. 

How to Know the Instance of a Ruling
The yardstick in specifying the instance of rulings is the determination of the mukallaf himself or his having a shar‘ī proof to that effect.

Transmiting a Mujtahid’s Fatwā
A person, who makes mistakes while transmiting a mujtahid’s fatwā, is not allowed to undertak this task.

To Follow the Most Learned Mujtahid
If there are several mujtahids who are qualified for issuing fatwās and their fatwās are different, it will be of obligatory caution upon the mukallaf to follow the most learned one.

A Definition for ‘Ādil 
A person, who is so pious that he would not commit a sin deliberately, is considered as ‘ādil.

To Change One's Taqlīd
By obligatory caution, it is not permissible to change one's taqlīd from a living mujtahid to another one unless the latter is/may be the most knowledgeable mujtahid.

To Follow Several Mujtahids Simultaneously
There is no problem with dividing one’s taqlīd between several mujtahids who are equal in knowledge.

To Follow a Deceased Mujtahid 
The permissibility of starting or continuing to follow a deceased mujtahid depends on the fatwā of a living mujtahid who is — by obligatory caution — the most learned one.

To Start Following a Deceased Mujtahid 
By obligatory caution, it is not permissible to start following a deceased mujtahid.

To Continue Following a Marji‘ after His Death
Continuing to follow a marji‘after his death even with regard to those issues which he has not acted upon during the life time of the marji‘, is permissible and valid.

To Follow a Deceased Mujtahid after a Living One
Before referring to a living mujtahid regarding a particular issue, it is permissible to continue with following a deceased marji‘. However, once you change in that issue to a living mujtahid, it is not permissible — by obligatory caution — to refer back to the deceased one.