Using plastic gloves (or just put a plastic bag over your hand) spread a REALLY thin layer over the cooler using your finger. This is simply just to fill any small grooves in the coolers surface. If you lap your cooler you don't need to do this.
Using a credit card spread a layer around 1mm thick on CPU, the main thing here is to just try and cover the whole area of the CPU that comes into contact with the cooler.
The most important thing is not to fret too much about this. Once you've put it all together, run a stress test and keep an eye on the CPU temp, if it goes too high, just clean the paste off and try again :)
According to ArcticSilver ( http://www.arcticsilver.com/pdf/appmeth/int/vl/intel_app_met... ) all CPU covered with an aluminium plate should have their thermal paste just put in a single vertical line in the center.
They also talk about the line surface spread method you're talking about but only for mobile CPUs.
My fear is that by spreading the paste with gloves I'd somehow add some air in the paste, resulting in really bad thermal conductivity.
It seems your method is the way to go, though: http://overclocking.guide/thermal-paste-roundup-2015-47-prod...
As for using gloves, you won't add an air pocket, as the gloves are only used for applying a really thin coating to the heatsink. By really thin, I mean just enough to be visible on the heatsink, while still being able to see the heatsink surface through the thermal paste. That should be enough to fill any gaps in the heatsink surface.
TLDR: if in doubt just use the small dot in the center method. the X if you're feeling creative
And yes, you just apply it to the cpu and when the heatsink presses on the cpu it will do the spreading by itself
If there are instructions available from the supplier I'd recommend sticking to that though because it seems like the different thermal paste brands behaves differently in terms of spreading.
Apply a pea-sized drop in the very center and you are done! (and resist the temptation to make it juust a little larger)
The pressure will spread it out evenly.
There was a video I saw where they did this using glass so you could how the paste spreads.