I have multiple Azure subscriptions linked to my account, so anytime I connect to Azure in PowerShell I have to make sure i am working in the right context. To simplify this I wrote a little helper function called Select-MyAzureRmSubscription.
After entering the -SubscriptionName parameter the script enumerates alll the subscriptions I have access to and generates a dynamic parameter option.
Script location on GitHub: https://github.com/alexverboon/posh/blob/master/Azure/Utilities/select-MyAzureRmSubscription.ps1