This is my first post here, so hello from the Jaded Isle (Ireland).
This may be oooold, or well-known, but here goes.
I've been practising my (lacklustre) DDP skills recently and found this neat trick.
A quick note about the screenshots, they're taken from a game where I just credit-pumped to the boss, for the purpose of taking these shots. The shots are not necessarily all from the same attempt, because taking screenshots and staying alive ain't easy.
This trick applies to the Area 2 boss. Only use bombs or super-laser when I say.
When you go in, he looks like this:

You blow off the far left and far right little boxes, getting the stars each time, which leaves you with this:

Then you blow the cap off each of the big internal cannons which leaves you with the following picture:

Note: Only blow off THE CAP. Doing this results in one star for each.
Both of the guns under the caps should now be shooting little red bullets. Drop a bomb and grab as many of the big stars as you can:

Hope this helps someone!
John