Some pointers:
- Glassing planets results in a huge value loss (~30%!)
- Morale is critical:  the 40% difference in production from Angry to Jubilant can make or break your empire.
- As a bloodthirsty race, battle victories are critical to happiness.
- Tactical Combat is critical to battle victories.  Unless you are can form a strategy to get 3 DNs to win against 15 Psychic Baseships, Tactical is nessesary.
- Remember the value of ship capture.  Taking a Baseship can net you over 3000 minerals, enough to run one of your DNs for 1/2 a year.
- Make good use of Nature Shrines, and monoliths.  You're in this for the long run, and the shrines should overcome the inevitable sabotage events.
- Always have two SpacePorts!  Losing your spaceport can potentially lose the game.
- Always have two spaceyards, but don't waste facility slots on them.  Use your construction ship to build two or more factory bases.
- Resupply depots are not critical.  You can fleet with a base, or use emergency supply pods.  Resupply bases are useful for fast turn around time, when you're trying to defend an empire with three ships, though 

.