Artillery...
	First wave...
	XP bonus perk...

Remember that artillery has to travel, so you might need to 'lead' your targets if you want to make a direct hit.

It is often worth scrapping out the first wave with your solitary flagship in order to see what is needed and use your resources effectively.

Early on, you might want to go with the XP bonus perk while the going's relatively easy so you can unlock some of the better ships quicker.