I have seen people create multiple budgets to manage EC2 instances, I don’t do that.
For my budget I create one and have that manage multiple services as per the picture below.
As you can see I have filters to watch out for specfic services, and these services are the only ones that I am running that are costing me credits. I do have Route 53 but that is a set charge of $0.50 cents and does not need to be monitored, but I do check it every day when I use AWS.
I believe this is just another way to optimise your AWS experiance.