Cloudabilty it awesome. AWS' Billing dashboard is also great for a quick view. The report I use most is one I created that is the "Daily Cost per API Operation

Cloudabilty it awesome. AWS' Billing dashboard is also great for a quick view. The report I use most is one I created that is the "Daily Cost per API Operation". Do the "Daily costs" report then group by API operation. I then view it by day (instead of month) for the last 3 cal months as a stacked bar graph. I also have a CloudWatch alarm set to trigger at a certain spend. That alarm should trigger around the same day of each month. That way if it triggers 7 (or whatever) days before expected, I know we may have a problem.