Bedtime math and this blog
http://letsplaymath.net/2009/04/06/buddy-math/both make a neat point about reading vs. other subjects. They say math, but I guess it applies to writing and everything else. Everybody loves reading, but many people hate math. They guess the reason this is might be that reading is relaxed and you do it in front of them way more than you ask them to do it. When you get to other subjects you kinda tell them, this is what you do- now do it and I'll tell you if you're wrong (although some people don't believe in telling kids they're wrong if they're trying). They suggest "you do a problem and I'll do a problem". I pre-homeschooled my kid for a few years. That's why I have more ideas than a kinder homeschooler usually would. I ask my kid and my husband bedtime math word problems when we're sitting around. He asks me word problems that he makes up. I do a lot of writing that he tells me to do, I also do the writing for the homework I assign while he just answers the questions. I know a lot of this can be done orally more easily, but I want him to see that the answers have to be written down, someone has to write the answers. I like how "The Well Trained Mind" and "Writing with Ease" by the same author says to take it easy on expecting the kids to write their answers through the second grade, unless the assignment is handwriting. Let them answer orally and you write it down. Only make them write it down sometimes for the practice. So for the seat time for Singapore math he sits with me and answers a few pages and I write it down. I write pretty slow so he's still sitting there getting his fifteen minutes of seat time in math. Sometimes he says, "You answer the questions and I'll write it down." That's fine too. If they were in a classroom they would not be answering every single question. Their classmates would answer some questions and that would be considered learning too.
Excuse typeos and lack of grammer, breaks, and formatting. Phone's out of battery so I'm going to hit post before editing for clarity.
