Ill break it down for you really fast, OP. Some of the advice here is on point, and some of it is misguided. I obtain flawless shiny smooth joints every time, using the following method.

1. I use a 10$ 40watt weller iron from home depot, with a wedge tip. It gets hotter than the $150 soldering station at my track
2. Use 60/40 rosin core solder from radio shack. RC brand solder is crap
3. Get a little tub of flux
4. I score the solder tab a bit with a scraper, pick, or file so its a little rough
5. Dab a tiny bit of flux on your twisted/stripped wire and the solder tab
6. Tin both the end of the wire and the solder tab. Only 4mm or so needs to tinned on the wire, make sure to not use too much, or too little. (tinning means to pre-apply some solder to the end before joining it with something else)
7. Use quality high strand count wire. I always use Deans wet noodle
8. Hold the wire onto the solder tab, and then use the iron to press the two together. Sometimes I RE-apply a tiny bit more of flux before I do that too.
9. If done right, the wire will sink into the tab in less than a second, and you're done.

I couldn't find any closeups of my solder joints, but this should give you an idea of what this technique and choice of products can do. One day i'll make a video.