They are awesome and can be done at any time and any stage of a unit. Keep short and sharp and kids may use what they have learned in the mini lesson or not. Stay away from lectures!
I have had a go at these with great success! E.g. Headlines, silent letters.
Identify leaning needs from Literacy Progressions:
Lexical Chain: Words that appear in different parts of the text that builds coherency. Rome... capital... city...
Also a pronoun reference: pronouns like 'they, them, it, you... etc.' need to be taught in a mini lesson. For example, tell children to highlight all pronouns then get them to ask themselves who is the 'it' talking about? Is it the Queen's Pajamas?
I need to let my children in term 4 make decisions about the text type that they want to.
Summary: keep looking at the 'By the end of Year 6' page and focus on one per term. Or until I feel confident to use them all together, dynamically and systematically.
Look more at a range of children's work to organise mini lessons around.
Carry on trying to do mini lessons. Keep being cool, and ask a lot of questions.