Got the first three - but still trying for DSII.
My tips:
1. Hoth Battle
On the opening section - grab the bomb and get it to blow open the doors as soon as possible - don't mess around trying to kill off a pile of stuff.
Second section - no special guide here - just get through it as per normal.
Final section where you get all the different empire stuff thrown at you - I found if you fly in spirals just cleaning out what is visble on the screen, before looping about half a screen left or right, you'll usually get enough warning of what's coming to blow it up without getting blown up yourself.
2. Falcon Flight
I use the method noted on another post somewhere - can't remember who so apologies.
For most of it, fly direct - blow up as little as possible to create minimum debris. Then when it comes down to the final big spinning rock - fly in circles in front of it, continually firing you blasters, while picking up torpedoes and dropping them in as the targets appear.
3. Speeders
To be honest, this one seemed pretty straightforward. - Use a ghost so that the bits on the ground are handled without dying. While on the speeders, don't feel the need to try to keep up reklessly with the troopers. They'll keep coming round and you'll get them eventually.
All the best.
- Iain