I am right there with you, struggling, struggling, struggling.
I can't say I've got a handle on everything, but I am working at it and things are getting better. Here's a few things working for me.
1. I decided that I MUST HAVE THE KITCHEN CLEAN or I will go insane. Because we all live in these houses that connect the kitchen to a living space, the whole space HAS to be generally tidy because I have to look at it so often. I asked my spouse to help me with this ONE SPACE for right now, making an extra effort not to drop his stuff there (bad example for the kids) and not to let them leave stuff all over either. In exchange, I promised him I would be cheerier, less prone to nag, etc. To his credit, he is trying and the room is cleaner because of it. It was also the start of developing better "putting away" habits.
2. I refuse to cook in a dirty kitchen. If they trash the kitchen between meals, they wait for their next meal. This makes an impression because they get hungry and there have been plenty of times I haven't even started dinner yet because I'm still CLEANING THEIR MESSES.
3. One room at a time I am planning better ways to store things so we actually have places to put things away. I'm dumping or giving away things we really don't need, rearranging furniture, buying or scrounging organizers, cabinets, etc. This is a slow process, but it's coming along. I've worked on three mess areas so far, the laundry room, our master closet, and our "office." We actually splurged and put cabinets in the laundry, and I'm still trying to figure out what to put away where.
4. Hooks and shoe racks. We put up about six hooks per child (we have three kids 11, 8, 6) at levels the kids can reach. Backpacks, jackets, etc, all go on the hooks. I also put a little shoe rack in the hall where the kids come in from the garage (see it here: http://www.amazon.com/Cedar-Shoe-Rack-Set-2/dp/B0009LBV4Y..., and shoe trees in the bottom of their closets (see these here: http://www.amazon.com/Whitney-Design-2131-18-Pair-Revolvi.... The girls seem to think it's fun to load shoes onto the shoe tree, and they all were more or less easily trained to drop their shoes on the hall rack when they come in.
5. Cubbies. I picked up some cute plastic tubs at Lowes and the kids decorated them. When I trip over something, I throw it into their "cubby." When they need to put something away fast and don't want to take it upstairs, they may throw it into their cubby. When cubbies get too full, we dump the contents and put stuff where it belongs.
6. I put piles of stuff to go upstairs on the steps. The kids seem much more willing to grab something and take it up when they are headed that way than to stop what they are playing to take stuff up RIGHT NOW!
7. Kids DO NOT EAT ANYWHERE THERE'S CARPET. Period, end of story. In our house that means we eat ONLY at the kitchen table or out on the patio. If you have to break habits of carrying food to bedrooms, to the TV set, etc, I feel sorry for you, but it's worth it. Our carpet is much happier for it. Not to mention, it really keeps the food clutter in one room. Of course, this rule gets broken by the GROWN-UPS constantly (me included) but that's just a privilege of adulthood.
8. Lastly, in our house, there is an attitude problem. My spouse (a spoiled youngest child) is as bad as the kids. I have to chase him down to get his attention. In fact, he thinks I should chase him down ("just remind me till I do it" is what he says to me)! I have pulled him aside more than once to tell him I do not need a fourth kid, and that I resent that he wants me to nag and nag and nag and nag like I have to do the kids. I have to say, having this conversation calmly (if repeatedly) has made at least some impression, coupled with a question about what he would think if someone had to chase me down to, say, bring groceries into the house!
It helps to laugh, so here is a funny story. The ONE lightbulb over my sink went out, leaving me to do hair and make-up in the dark. Yes, I could have changed it myself, but this is "his job" so I didn't. I told him it was burned out about half a dozen times over the course of a week, but got no action. Finally, I climbed up and unscrewed just slightly both of the bulbs over HIS sink, leaving him in the dark. THAT moved him. By the end of the day, he was in the bathroom with bulbs. I was fortunate to have the pleasure of being in the room when he showed up with the bulbs. He climbed up on my sink first, and changed the bulb. As soon as he did, I climbed up on his and screwed both the bulbs back tight and turned the light on. Even he saw the humor in this.
Keep smiling ladies. A clean house is under that mess just waiting to be discovered!