I always find it a bit frustrating when the kids have to make some object for homework (e.g. a viking longhouse, a palace etc.) and then you see some that are brought along and they have obviously been made by the parents - it ends up in a competition between them rather than the kids. Other than help with supplying material, and holding bits while they stick them etc, I have always let my kids make them themselves. My younger son was really upset when he didn't win a prize one year for the puppet he had made and the puppet that won had clearly been made by a parent. Not that he would have necessarily have won anyway, but that simply isn't fair. As for normal homework, I expect my kids at 8 & 9 to do homework when required and to come and ask me if there is anything that they don't understand and then I am happy to guide them, but won't do it for them. If they don't do their homework to an acceptable standard, then they have to deal with that, it's their homework not mine. That might seem hard, but I like them to take responsibility and the consequences.
In my view, the homework they get is a bit of an afterthought and seems to be given out purely as a bit of a waste of time exercise. When in the infants, I agree that the work given needs to be supported so that parents can view progress etc and the lessons need to be reinforced, but as they get older some of it does seems to be a waste of time, I'd rather they had something meaningful or nothing at all. To be fair, I am lucky that my kids don't struggle with their work, if they did, maybe I would find it more useful.