What is the best way the instructor should follow when givingEnglish lessons; is it through following a text book or sharing information & discussion?

of course through sharing information and discussion

Go through the lesson, get input from students and questions, then proceed to answer and clarify.

In English lessons the best way to instruct. teach or impart knowledge is for learners to understand first hand what he or she is expected to learn.  For example, if you want a child to learn what the sea is take the child to the sea.  In most cases it is not possible for someone to have first hand experiences.  This means that one can introduce learners to second hand experience which could be a picture, a textbook or a computer generated scenario that compensates for  the lack of the first hand experience. Depending on what is taught, textbooks and discussion is always important.  However, the should be sufficient discussion in introducing any concept.  In other words learners should benefit from pre-knowledge before they are introduced to a concept.  In the final analysis the conditions must be created for the learner to interact with the new knowledge.  Real leaning takes place where there is sufficient understanding.  So one could use first hand experiences, textbooks, computers or discussions provided that there is sufficient focus on meaning and understanding

use of short sentences, multiple color makers and providing relevant examples

an instructor who shares information and open discussion when giving Lessons is using the best way