Cull the toys. I find DD is more bored, the more toys she has, it's like the choice paralyses her. Plus they're easier to tidy if you have only enough toys that fit in places in your house! The other option I've done, is rotate toys via the attic. So have a cull, then put half in the attic. In 6mo, rotate them around. It's like having new toys
. I didn't think this would work but I've just got the Happyland down for DS, and DD (nearly 6yo) has been playing with it loads.
Don't bother cleaning the hidden spots (they're hidden!)
I've paid to have our oven cleaned. It costs a bit but they make an excellent job of it, it looked brand new. Otherwise I find it's actually not so bad when I do it, seems a bigger job in my head. I get the bags you put the stuff in to do the shelves and then Mr Muscle foam to do the sides and glass in the door.
I clean out our fridge once a year. I put some kitchen roll at the bottom of the veg drawers to absorb any condensation and wipe up any spills when they happen. Most things are in packets so there's not much to get spilt.
Cull the kitchen crap too. I try to get rid of as many kitchen gadgets/dishes/utensils that we don't use as possible. Therefore keeping the sides as empty as I can to make wiping down really quick. The more stuff you need to wipe around, the longer it takes! Also, there's less stuff gathering dust and looking dirty on the sides. Easier said than done if you have a small kitchen (we've been there with a 2m square kitchen), but it's amazing how much you don't actually need.
Also, I've found our kitchen appears cleaner now we have a dishwasher... I keep it ready for loading all the time, so any dirties go straight in (therefore not on the side and out of sight). Plus the added bonus of an induction hob, where it's just a glass top, 30 secs to wipe over and it's clean. I used to hate cleaning the gas hob in our old house.
The house admin is tricky when you have two pre-schoolers during the day. I've tended to take time of work and blitzed it, when I've got loads. Just sat on the floor in the lounge with the shredder, filing box and naff TV. Impossible with kids around. Going forward, I just keep one magazine file in the kitchen, when it's full it forces me to do it, so it become an hour job rather than a half day job! I also photograph on my phone important school letters etc, then recycle the paper copies. Keeps the paper to a minimum.
Our house often still needs a good hoover and steam clean, but we only have one school age DC and I'm due DC2 any day now. Is significantly harder with more children at home.