bleeding brakes

Something not mentioned here and often overlooked is to flush the old fluid out when you bother to bleed the brakes.
After removing the reservoir lid extract the fluid in it(an old turkey baster works for this)and refill it with fresh fluid. This way you'll get fresh fluid circulated immediately rather than just diluting the old as the level gets low.
Brake fluid is hydrophilic and all that absorbed moisture is what kills brake systems. The boiling point is also effected negatively when moisture is present.