My boat is in Ensenada getting finished up. Last time I was there I moved her from one marina to another. Calm weather and I was alone. I'm rusty these days, but still consider myself a pretty fair close quarter helmsman. I failed to notice a slight current and as I backed out into a somewhat narrow fairway, I could not get my bow turned out into the fairway. Frankly, I was in a bit of unexpected trouble......until Viktor, a dock hand I'd befriended during my stay, came to my rescue and pushed my bow through for me. I was humbled to say the least. I've had a few memorable learning experiences that started with hubris (one Angel Island in SF Bay comes instantly to mind - what a cluster)
My point is that docking is highly variable based on conditions of course, but also boat and crew. Especially when it cones to spring lines, what works on one boat will often yield unexpected results on a different boat. There's often a healthy gap between theory and reality so online advice columns are unreliable at best, and unfortunately can be counterproductive because they often give the impression the troubled helmsman just isn't doing it right, that there is a simple procedure that would cure his woes.
Psneeld mentioned Chapman's has a good section on springlines. If so, see how they work on your boat, but do so in calm conditions. I know, you won't need them in calm conditions but you need to first understand how the boat moves. Springlines are all about leverage, which means you have to identify the best fulcrum points to set fenders to pivot. You need to develop muscle memory and test your equipment- many boats have lines long enough to double-back so crew can work from the boat vs the dock.
I do firmly believe in thrusters, especially for single engine trawlers. I know all the workarounds but none totally equal the close quarter maneuverability of an adequately sized thruster. And I know the arguments for not having or not relying on a thruster.
The bulk of my recreational boating has been in SF Bay where afternoon winds are almost always 25 kts on the Bay, and in the high teens at docks when you return. Like many people, I started by being terrified to go out for fear of conditions when I returned - and that was on a Uniflite 42 with twin screws (I was a novice/lousy helmsman back then). I would have gotten so much more use out of that boat if I had had a thruster.
There are no magic bullets. If my opening story of being in trouble in Ensenada reminds me of anything, it's that not all docking problems have a solution. Sometimes it's best to just wait and let conditions improve. Or have the good fortune to have Viktor come to the rescue.
Peter