If you do not want to use a mnemonic (and let's face it, they aren't much good if you are unable to recall what the letters stand for!), you can link it into a scene using your imagination.
When I think of networking I think of my local PC world store.
This is the scene for my 7 layers.
In the shop I can see someone doing some Physical exercise.
But it isnt a person, its a robot and they have a Datalink cable plugged into its foot!
I follow the cable and I see it is connected to a rather large computer that has a big picture of a train on the screen.
It is blowing its whistle too. The train represents Transport.
Session makes me think of sachet of ketchup. I imagine seeing sachets dropping out of the computer screen and splattering all over the floor.
But all the burst sachets of ketchup are ruining a lovely Presentation a sales person is doing for a customer in the store. Their big white presentation pad is getting covered with red ketchup.
The sales person gets out an Application form for the customer so sign so as they can seal the deal but the customer says no as the Application form is covered with ketchup!