Lindbergh's success was no accident. He was meticulous a planner with an eye for detail. His time flying the mail in all kinds of foul weather had prepared him for the trials of the North Atlantic but it was his logical decision making process that served him best.
The decision to use a single engine plane was beautiful in its simplicity. If the Spirit had been a multi engine plane, it would have simply increased the odds of an engine failure with every engine added. Two engines gives you twice as many points of failure. It is unlikely that such a heavily fuel laden plane could have stayed aloft with an engine out (at least within the first hours of the flight). using the kiss philosophy (Keep It Sweet & Simple) held down costs and risks. This is why he chose the Wright J5-C Whirlwind engine. It had a sterling reputation for reliability.
No radio. Lindbergh knew that having a radio would add considerable weight and little value. Once committed to the flight knowing about the weather ahead was not going to change it and if he went in the ocean, hypothermia would probably get him before help did. The over water navigation had to be by dead reckoning since there were no over water navigational aids. Again, a well calculated risk.
Keep it light. Lindbergh was a hawk when it came to keeping the plane light. Every pound he saved was a another pound of fuel. He never sacrificed the structure or soundness of the plane but he omitted anything that he did not absolutely need. Even his survival kit was minimal. As a result he was able to putter along at 108 miles per hour to a safe landing at Le Bourget filed in Paris, France 33 hours and 29 minutes after takeoff.
Planning, planning, planning. Lindbergh thought everything through. His flight was carefully planned despite pressure to go from competitors. His biggest mistake was going without sufficient rest but and the conditions were far from ideal. Despite this he had received all available weather reports and did not launch until mother nature said it was OK to do so. This sound, if not rushed thinking kept him alive. Again, the careful planning made sure it all worked out in the end.