One thing you can do is have them strike multiple targets.
So you set them to release their bombs/rockets on a specific target. The waypoint should become a triangle.
Then create 2 more regular (turn) waypoints close to the
target. Create another strike waypoint (triangle) and
have them attack with guns on another target.  It also
helps to use the 'strike' or 'seek and destroy' mission
type for the flight. The aircraft are more aggressive IMO
when these types are used.

For each target they spend a lot of time setting up for it,
and respond aggressivley if they are attacked at this point. This method will keep them in the area, and
hostile, longer instead of meekly puttering around.
hehehe.