Billing alarms for your AWS account!
TL;DR Omg, stop wasting money without noticing it!
My sacred bill
You are a developer, a sandbox-player, a researcher, a poc-er, BUT not a cleaner..
You make beautiful sandbox projects, you are continuously exploring the limits of the cloud.
However, you forget to clean up unnecessary resources!
I am blaiming you, but actually it is me. And if you are here, maybe your are like me. 
A solution
Billing alarms is what I need!
How do I configure them?
How do I set them up?
There is a cloudformation template for that, right?!
Indeed, I went looking for a solution and found a repository by Dimitri Tarasowski.
You can use the following gist:
| AWSTemplateFormatVersion: "2010-09-09" | |
| Description: Billing Alerts for your AWS Account | |
| Parameters: | |
| Email: | |
| Type: String | |
| Default: youremail@somerandomdomain.com | |
| Description: The email address to receive alerts per email | |
| Phone: | |
| Type: String | |
| Default: "+3212312828345" | |
| Description: The mobile phone number to receive SMS message alerts | |
| Mappings: | |
| EstimatedCharges: | |
| AlarmRange: | |
| "Threshold": 10 # Triggers an alarm if charges go above $10 | |
| Resources: | |
| BillingAlert: | |
| Type: AWS::CloudWatch::Alarm | |
| Properties: | |
| AlarmActions: | |
| - !Ref BillingAlertTopic | |
| AlarmDescription: | |
| !Join [ | |
| "", | |
| [Alert for $, !FindInMap [EstimatedCharges, AlarmRange, Threshold]], | |
| ] | |
| ComparisonOperator: GreaterThanThreshold | |
| Dimensions: | |
| - Name: Currency | |
| Value: USD | |
| EvaluationPeriods: 1 | |
| MetricName: EstimatedCharges | |
| Namespace: AWS/Billing | |
| Period: 21600 | |
| TreatMissingData: ignore | |
| Statistic: Maximum | |
| Threshold: !FindInMap [EstimatedCharges, AlarmRange, One] | |
| BillingAlertTopic: | |
| Type: AWS::SNS::Topic | |
| AlarmSubscriberEmail: | |
| Type: AWS::SNS::Subscription | |
| Properties: | |
| Endpoint: !Ref Email | |
| Protocol: email | |
| TopicArn: !Ref BillingAlertTopic | |
| AlarmSubscriberSMS: | |
| Type: AWS::SNS::Subscription | |
| Properties: | |
| Endpoint: !Ref Phone | |
| Protocol: sms | |
| TopicArn: !Ref BillingAlertTopic |
Or check out this repository: https://github.com/Nxtra/aws-billing-alarms.
Run the following command to deploy the stack. Don't forget to update your email and phone number.
aws cloudformation deploy --template template.yaml --stack-name billing-alerts --capabilities CAPABILITY_IAM --region us-east-1 --parameter-overrides Email=YOUR_EMAIL Phone=YOUR_PHONE_NUMBER
Confirm the subscription via the email you've received.
And of you go, you will now get an sms and email when you go above your budget thresholds!
You can check the current status in cloudwatch too:
Be proactive and protect yourself against yourself. 
Credits
Featured image by Pepi Stojanovski on Unsplash.