The first couple of times I flared a tube in a handle, I used a brake/gas line flaring tool and got pretty good results. I flared one end of the tube by itself first, put it in the handle and used the flaring part from the tool in a vise to do the other side. The hardest part was getting the flaring part off of the tool.
I've since made a special tool to do it out of 1" square tube and 3/4" all thread rod. The body is made from the 1" square tubing, about the size of a 4"x6" (inside) picture frame. Think of a C clamp only more like a squared O with the threaded part in the middle. The flaring bits look a lot like the spinners shown in the link from greatlakeswaterjet. I cut and nicely deburr the stainless tube to the right length and put it in the handle. Line it up in the flaring tool and tighten it down. The stainless liner flares really easy and looks very nice. I ground the "spinners" to match the angle of a standard drill bit (63 degrees?). That way I counter sink the hole approx. 3/32" and the liner flares to the same angle and is inset.
