Really the only thing you can do is practice practice practice.
Change your settings to give you the most lives to start with, with extends at every 2 million points. If you're good with the first level, chaining it should get you to, or very close to an extra life.
After that, I suggest doing nothing fancy if you're not fantastic at the game. Try to be cautious and not risk your lives.
It's much easier with two playerss, just don't do anything stupid.
Spend a lot of time getting familiar with the enemy patterns on each level before attempting this