Create a named profile by opening your command line utility after installing the aws cli tools.
aws configure --profile hackbaby
Secret Access Key
Now you have set a named profile (you can set multiple)
Now...to make switching back and forth without a headache. Set your environment variables:
Window$: setx AWS_PROFILE hackbaby
Linux: export AWS_PROFILE=hackbaby
Close your command line tool. Re-open and then get to work. Close and re-open to flip between CLI profiles.