The oillines on my bike are AN 6 size stainless with highperformance fittings, the best way to mount the anodized aluminum fittings is to tightly tape around the braided hose on the place you want to cut. I use a very thin grinder disc on my Dremel to get a clean cut.
The old oiltank bracket on my center downtube was in the way and I was not happy with the way the oillines looked, so I removed the old bracket and started over. I painted the bare metal where I removed the bracket with a black hammerite spraycan, and rerouted the oilines. This time it looked much better! I'll probably be stripping the whole bike this winter, so I'll clean up the ugly spots on the frame then.