Just some general tips for achieving this as basically for each level it's just learning when to strategically use your bomb. Also, personally I'm using the laser gunship (the second one) as it seems easier to kill enemies.
1. Try to get past the first area without using your bomb, and save it for the first boss. It is possible with practice as I am able to achieve this almost every time now.
2. Just before the last boss is where I found it best to use my second bomb as the screen becomes far to crowded with bullets and enemies to feasible avoid an live past on a regular basis.
Any other general tips you may have, leave in the comments and I'll add them.