I enter the marina traveling W - slowly. As my lane comes abeam, I'll turn SW and give enough reverse to stop motion. I can't go too far, as there's a rock retaining wall. More reverse will get me moving N, stern first. As soon as I have way in reverse, the throttle goes back to idle. Tiller to port at the proper time brings me stern first into my slip, facing E. As the cockpit passes the SE piling, I grab the spring line and drop it over a winch. The spring line is pre-adjusted to keep the stern off the dock. In normal conditions, I do this single handed.
In abnormal conditions, you just have to see what the boat wants to do. I have found that more throttle and more speed are not good - invitations to trouble.
Leaving the slip & turning S sometimes needs a spring line to help make the turn - it's not a wide lane.