Can or should i use compression fittings instead of double-flares? I'm having problems getting a perfect double flare and running out of line because of many unsuccessful attempts.

Example: http://volksweb.relitech.com/brakeln.htm

 

Brake lines have to be flared. Try practicing on a spare or old line and then when you get it right, do it on the car.

 

Have any pictures of your failed flares? What flare are you trying to make anyway, was not clear from your previous post because you did mention a bubble flare. If its a double, I can offer some advice. It takes time, patience, and a little bit of tweaking the tools.