Homework- we opt out until year 5...but two of my kids started of their own accord before then.
However, we do do readers until they get to levels where they are essentially a chapter in a book and then we just switch to books (year 1-2 depending on how fast the individual child picked it up).
It is so easy to re-inforce what a child is learning in kindergaten without filling out worksheets.
Eg- asking them to write out shopping lists, christmas wish lists, birhday wish lists, letters to family members that you can post with a picture, asking your child how you spell a word when you are writing something down (our kids got a spelling list each week so I'd do it with those words)...spelling bees in the car with the same words (they get to quiz you on any word they want as well), and adding up letterbox numbers on walks. But if you want to sit down and do the homework sheets, one of my friend's has an early riser so homework gets done before school while the child is fresh.
Also...make lunches the night before...makes life easier of a morning!