Nickel can be difficult, especially in the smaller sizes. It is very soft. Try winding your coils around a rod about 2.5 mm in diameter. You can wild the coil spaced. Give yourself 6 to 8 turns. After winding, gently compress the coil winds together and let go. They should spring back slightly giving you nicely spaced windings. With nickel, you don't want the coils windings touching each other.
Leaving the coil on the rod, place it on the build deck and fasten the wires in place to the posts. Use the rod to manipulate the coil into proper position. Then gently rotate and slide the rod out. Carefully pull cotton through the coil, not tightly or it will disturb coil spacing and alignment. Finish wicking, juice up and enjoy. Start at a lower temp and work up.
First caveat: With that tiny of nickel, your posts must have screws to capture the wire. The posts that have a hole and pinch the wire as the screw is tightened will not work very well. The soft nickel wire usually breaks before a really good connection can be made.
Second: The istick TC40w fires everything at 40 watts up to temp setting. It's gonna fire that 30 gauge up to hot real quick like. I would highly recommend going to a 28 gave minimum; I use 26 with that mod.