I am bad with receipts too. what I do to make it easier is I shove all my receipts in the cupboard. when I get a stack I go through them all and write it in a book. So for example I put
Jan 7, 2014 (date) - Walmart (place) - 5km (km driven) - $100 (total spent) - Toys (description). then I file it away in my folder under the appropriate place. Then at the end of the year (because I am a procrastinator and don't do it until tax time) I enter all the info into a spreadsheet that I created. I then can make the computer do all the totalling and I can organize everything according to description so all my grocery totals are together (house and daycare are together and I claim 50%), all daycare toys are together etc. It then gives me a total of km's driven during the year so my accountant can figure out how much mileage to claim. I then have a full printout of all expenses and don't have to go looking at receipts anymore. I print my spreadsheet and that is what I give my accountant.