slowlyburning you mentioned on your Chat thread about paperwork - that's one area I have controlled now. I bought basic A4 files from Staples and filled them with those punched plastic pockets. Everything "useful" is filed in alphabetical order, I put a sticker on the pocket and write on it. For instance mine include Council Tax/Gas & elec/TV license/Tax DH/Tax me/Mitsubishi V5 and service/Driving licences (paper copies)/Child Trust fund DD2/Child Trust fund DD3/Hospital letters, and so on. Whenever I add anything new to the front of the pocket, I look at the rest of the paperwork in there to see if it is still current eg I only keep the last 2 years' utility bills (in fact that will stop as gone paperless billing now). I have a separate folder for bank statements, though again I have now switched to paperless so will not have any more to add.
I have 2 separate A4 files marked "guarantees/receipts/instruction booklets" where I file these. I do have to remember to go through these about once a year just to chuck out instructions for things we no longer have, or old receipts that are well out of warranty.
We have an Ikea chalkboard in the kitchen - on the chalkboard (magnetic) we put vouchers to be used soon eg the Sainsbury's petrol vouchers so one of us can take it when we go out. I also scribble on there anything we need to buy when out shopping, or something to remember to do, and which days the kids are school lunches. I try not to put much on there else no one looks at it. On the shelf underneath to one side go any tickets/things to do in the order they happen, plus on the other side takeaway menus. Eg at the moment my pieces of paper are in the order of preschool fun day details, Year R induction dates, dance show rehearsals, dance show tickets, Olympic tickets.
We have an Organised Mum diary on a recipe book stand in the kitchen - doesn't always work perfectly but the idea is that anything that is going to happen goes in there, and to check it before agreeing to go anywhere/do anything. (Could go electronic but I have an iPhone and DH has a work Blackberry that can't be synced to Outlook or similar due to firewalls so would be too much hassle, paper is quicker!)
The post is dealt with every day - filed or binned or put on the going-to-happen shelf. Any money off vouchers go in a little plastic envelope thing I keep in my handbag.
Ikea notice board
As a bonus there are 2 hooks underneath so DH and I put our car keys there when we get in (kitchen slap bang in middle of house so no chance of any fishing rod through a letterbox burglars!)