It isn't entirely different from copper, same principles apply: heat control is paramount, clean welll flux thoroughly, heat where you want the solder to flow to, be careful about not adding the solder from so many places that you encircle a dry spot, etc... But as said it is also different. It's like walking uphill, same basic principle for climbing mount Everest, but it is going to take a while longer to acclimatize to Everest.

Water bottle mounts are about the easiest to braze there is, you make you hole, peel back you paint, fit, clean, flux, and point and shoot, periodically touch the base with the wire, and all of a sudden it will suck in and self level, play flame to draw around. If the insert seems unstable before you start, you can balance a heavy metal thing on it, or from something adjacent to it, to hold it in place. Do not flux inside the part or to the hold down, or you will end up with a lot of solder where you don't want it. you can also wire it down, though I tend to end up with stuff attached to the frame when I do that.