When I first tried my hand at soldering I was using the "butter knife" method: apply solder to the iron, then try to smear it onto the wire like spreading butter with a butter knife. Of course the solder would never stick to where I wanted it to go. I had to learn that solder goes to where the heat is, so I instead had to heat the components or wires instead and then feed the solder onto the hot components. I also had to learn that a soldering iron is not a pencil, sometimes even when doing small parts you want to use the large tip. Don't try to tell the solder where to go, instead apply a big blog and watch it snap into place on its own.
Last year I installed an HDMI mod[1] into my Wii, this has been so far the hardest project. It took me many attempts to get it right, mainly because I was working against the solder instead of with it. But now that I have succeeded I could easily do it over and over again (not keen on the disassembly and reassembly of the console though).
EDIT: while I'm at it I might as well mention the iron I was using: the Pinecil[2]. It's a really neat and fast soldering iron at a very cheap price. Great for people like me who don't want hardware store cheap garbage, but also cannot justify buying an entire soldering station.
[1] https://electron-shepherd.com/collections/kits-mods/products... [2] https://pine64.com/product/pinecil-smart-mini-portable-solde...