Our Shaykh, Muḥammad ibn Ḥizām -may Allāh preserve him- was asked the following question:
Question: The questioner says: What is the difference between ittibā' and Taqlīd?
Answer: Ittibā' is to follow an imām based on evidence which he provides from the Sharī'ah; this is called ittibā' - not taqlīd. It is not blameworthy to refer to oneself as a follower of a particular Imām/scholar - if this is based on evidence. The evidence for that i.e. to say that I follow Imām so-and-so intending by that adherence to the Sharī‘ evidences, is the ḥadīth of Al-Irbādh ibn Ṣāriyah; that the Messenger of Allāh ﷺ said:
"Adhere to my Sunnah and the Sunnah of the rightly guided Caliphs. Cling firmly to it with your molars."
A more explicit evidence is the saying of Allāh - in reference to the Companions, may Allāh be pleased with them all:
{وَٱلسَّـٰبِقُونَ ٱلۡأَوَّلُونَ مِنَ ٱلۡمُهَـٰجِرِینَ وَٱلۡأَنصَارِ وَٱلَّذِینَ ٱتَّبَعُوهُم بِإِحۡسَـٰنࣲ}
“As for the foremost—the first of the Emigrants and the Helpers—and those who follow them (ittaba‘ūhum) in goodness,”
[Sūrah At-Tawbah 100]
So He (The Almighty) called that ittibā‘; although what's intended is adhering to the Sharī‘ evidences.
Similarly, the saying of Allāh:
{وَمَن یُشَاقِقِ ٱلرَّسُولَ مِنۢ بَعۡدِ مَا تَبَیَّنَ لَهُ ٱلۡهُدَىٰ وَیَتَّبِعۡ غَیۡرَ سَبِیلِ ٱلۡمُؤۡمِنِینَ}
“And whoever defies the Messenger after guidance has become clear to them and follows a path (yattabi‘) other than that of the believers,”
[Sūrah An-Nisā' 115]
