[Suicide Junkie]

In the designs menu, click the stats/strategy to switch from component view to stats. The default ship strategy can be changed by clicking the down arrow beside the current strategy.

When you have a fleet selected, you can change the Strategy and Formation of it by Clicking the strategy order icon (looks like a chess pawn)

To create custom strategies, click the crown for the Empire Status window, and choose strategies on the right.
Click Add, give it a name, and then set the movement, firing, damage/overkill amount, launching patterns and formation breaking pattern.
This new strategy will now be an option for your ships and fleets.