I reviewed the writing process at the beginning of the year and a few basic grammar rules (capital letters, commas in lists, quotes, run on's - I just allow them two connecting words per sentence). All I did is hold up the paper with the rule and review it, or sometimes write it on the board and have one of them come and put in the punctuation. It only took one or two minutes at most. You could put these reminders on a bulletin board. I reviewed the basic rules quickly each day before they wrote.
I found that the children never applied anything from from any formal mini lesson. so it was a waste of time. They could answer test questions correctly, but it didn't seem to transfer into their writing. I just kept working with the children as they wrote to get them to apply writing principles and rules.
Do you start first in 3rd grade with how to write a paragraph or does it just come naturally after a while?
The concept of paragraph is difficult for third grade students. First they need to understand what makes a sentence. They seem to understand the concept of grouping sentences into paragraphs best when they see it in their own writing. I explain paragraphs as a warning given to the reader that you are making a change - in who is speaking, in time, in place, or in idea.
When I read their draft, I point out when they are making a change in something, mark that spot with the paragraph symbol, then have them recopy it with paragraphs.
Do you give topics for the whole class to write about or do you let them write about anything they are interested in?
For their very first writing I ask them to write about themselves. We read "About Me" in groups and it helps them to get to know each other and feel more comfortable about sharing their writing. The rest of the time I let them write whatever they want. Their eyes light up and they can hardly believe that they can really do something they want to do! Children are so creative! I wonder why we, as adults, often feel that we have to supply them with ideas. I also find that children often have an excellent sense of language and feel for writing. All they need is a little help refining how to communicate their ideas.
If the child has some emotional feeling about their writing, it is much easier for them to write. Writing about something they want to write about gives them an enthusiasm for writing and allows them to experience the purpose of writing -- to communicate.
They have a writing book, "Write on Track", which has examples of many types of writing. When a child needs more challenge, I suggest another type to them and refer them to the book for examples. When one child tries a different type of writing, I allow them to read their writing in front of the whole class. I praise and explain what they have done and challenge the rest of the class to try that type of writing. Sometimes I do this in a small group of top writers if the rest of the class isn't ready for this type of writing yet. Some have tried poems (alliteration, metaphors, personification, acrostic from etc).
I have them all write an acrostic poem for Halloween (the boys love this!) and they write a report (expository essay form) which I help them complete. After they have experience with narrative writing with a good beginning, middle, and end, they can do this pretty easily.
Generally, they begin with narrative writing - trips they have taken, about their family, and accidents (lots of accidents!). Until they can write a clear, well organized, narrative, I don't challenge them to write any other type of writing. A few of the struggling students take all year to master basic writing, but the eventually get there.
My goal is to help them learn to communicate in writing- not pass requirements. I think you could cover a type briefly, then continue coaching their writing.
The main thing is to have them write. You would never give a lesson on swimming, dance, or baseball, then expect the child to be able to do it, but would give a brief demonstration, then get them out in the water, floor, or diamond to practice. All the while you would coach and encourage them. This works with writing too. I just have them write, then coach them on what they individually need. Giving them positive feedback while they are actually writing instead of when they are "done" keeps them from becoming discouraged.
What about narrative, persuasive, expository essays? Now with Common Core there is so much more we need to be doing to meet the criteria. You must teach to the tests, but coaching will teach them to write.
Hope this helps.