how can i make higher resolution titles?

The general rules are - use a sans-serif font (for example, Arial) and make it as large as you can, subject to the limits of your aesthetic tolerance. Small fonts & serif fonts do not work well in video.

I don't know if FCE 1.1 included Title 3D, but that generator includes a 1:2:1 Deflicker control that may be helpful. If not, you could try adding the Flicker Filter to your text clip.

Another suggestion (and I'm assuming you have still text, not moving text) would be to duplicate the text clip and stack it on top of the original text clip, on a higher video track. Then open the original text clip and apply the Gaussian Blur filter or Anti-Alias filter. This will help soften the pixellated edges of the text.

Which generator(s) are you using, what font & what size?

Yes, you really need to watch the video on a video monitor to see the real quality. It will look different compared to your computer monitor. Lower Third has always worked well for me.