Tools required: Welding gear, a drill, tin snips, pliers, small ball ended hammer, round file, hacksaw.
Helpful: Angle grinder, milling machine
Materials required; Thin sheet steel (0.5mm ideally), some tubing of different sizes (but around 10-16mm OD ideally), a GU10 bulb holder, wiring connectors and wire.
Step 1: Making the stalk
First, cut the length you think looks about right of 16mm tube, and using an angle grinder or hacksaw cut a cross about 6mm deep into the end.
Using a drift of some kind (you can even use the 6mm rod) flare out two opposing sections as shown in the photo. Also slightly squash in the other two. Your 10mm tube should fit nicely in at an angle. when choosing the angle to fit it at, bear in mind you have to feed some wire through it, so don't make it too acute! Tack weld it in place.
Then fit your 6mm rod in place and weld at an opposing angle, however you like. Weld all round and weld the slots up, grind/ file the welds back to make it look better.
I bent a slight 'S' curve into the 10 and 6mm stuff, and left the 16mm straight. But do whatever looks right to you!
I finished the stalk by cutting slight striations into it with an angle grinder to make it look more organic...