[Gryphin]

Growtigga: Heads up!
The key to most strategic victories are:
Concentration of Effort, Ecconmy of Force, Mobility, and Flexibilty. (Addapted and modified ro game terms from Zun Sue The Art of War and a US Army Training Manuel)

Like you, at the moment I only play against the AI, but sometime soon, Growltigga and I hope to have a trans Atlantic game going, (PBEM).

My notes are mostly kept in separate files:
Specific to the current game
Apply to SE IV game mechanics.
Possible Strategies
Possible Tactics
Surprises
AI Behavior

Within the "Current Game"
It has always been my experiance that changing strategies part way though any endevor can be a big mistake are requires signifigant analasys before doing so. This does not mean you should not take the time to develop Point Defence Cannons if you run into a race using fighters or Cap Shp Mis,
Selected Global Strategy, IE: How I intend to "$X" the game as well as any details such as Facillities, Tech Trees I intend to complete in what order.
I tend to organize by "Front"
Then Solar Systems within the Front
Notes specific to AI actions and my intentions.

There is much more, but over all, it will be determined by your developping "Play Style".
Enjoy