if you are going to use rubber lines make sure you clamp them good. And if your just gonna slip it over a steel line then clamp it you should flare the line before you slip it over. That will give you some extra grip.
In the past ive just gone to a hardware store and picked up some copper tubing. It flares real easy, and accepts brake fittings. Bends pretty easy too. On the truck im building now i have aluminum lines i got through speedway motors. Dont quote me on this, but i'll bet copper tubing from lowes is the same price or cheaper than the good rubber line you get from the autopart store. 10foot for $9 at Lowes.