C# - Constructs/patterns Do You Use For Accessing State?

Let's say you're building something simple, like a data entry/CRUD form for working on an entity called Customer. Maybe you pass the CustomerID in via Session state.I tend to write a lot of fairly boilerplate plumbing code around handling that Session variable in a particular way. The goals vary slightly but tend to be things like:

Avoid cluttering the main flow of the page with plumbing code

Handle the back button intelligently

Remove the variable from Session and persist it to ViewState ASAP

Code defensively for failure situations where the state doesn't get passed, or is lost

Do you have a best practice for handling this situation? Do you have classes in your stack that handle this perfectly every time? Do you just call the Session variables directly? Do you use encrypted QueryString and avoid Session variables in this situation entirely in order to make the back button work a little better?Lately I've been using Properties with Session variables. Here's a simple example that I just threw together, although please keep in mind that this example would not be very tolerant of the back button:

Private ReadOnly Property CustomerID() As Integer
Get
If Me.ViewState(Constants.CustomerID) Is Nothing Then[code]....