Creating and using effective and correct fingering for piano music, especially complex or advanced classical music is one of the most important steps in learning the music. In more advanced music, there may be various options for fingering certain passages, and knowing which fingerings to choose, and why, is a valuable skill to learn. Many of the printed fingerings are not practical, or even possible for students with small hands, and everyone’s hands are slightly different, so what works well for one person may not work at all for another. Below are some guidelines to follow when choosing fingerings.

The fingering must allow you to deliver correct phrasing and articulation as indicated by the music and by the composer.
Once you have considered rule #1, then go for smoothness and ease of execution.
In general, keep the thumbs off the black keys, especially and always on scale passages.
Think of hand positions and chords
Keep it simple, and don’t move unless you need to. The less moving around, the better.
When you do have to move to another position, and you have a choice of moving earlier or later, move earlier, even if it is by one note.
Be ready and willing to change the fingering that you have so diligently practiced if you discover, perhaps by accident, a more effective fingering that will give you more ease of motion while still observing the rules above.
If you follow these basic rules, you can be comfortable moving around on the keyboard, while still serving the music, which is the goal of rule #1.