Trill fingerings are so interesting: they are not 'one size fits all' as we first learned them! I find some of the basic fingerings lacking in pitch accuracy: the top note might be too flat or the tone quality too false. Occasionally, there is a magical mechanical fix, such as the C# trill key. It is one of the best investments not only for the B-C# trill but for third octave G-A trill, so I highly recommend this particular key as an option when purchasing a flute. One of my favorite sources for alternative fingerings is Nestor Herszbaum's book "Alternative Fingerings for the Flute". It has many different solutions which are helpful depending on the color/pitch you might require. One of my current finds is the third octave E-F# fingering. The typical thumb trill yields a very flat F#. Try fingering A natural with the left hand, right hand on 2nd trill key and trill with the A key in the left hand...so much better.
The Details make the Style
Many times students come to us for coaching on a piece right before a competition or an audition, so our job as their coach is to help them polish and refine the piece at hand. It's always amazing to me how much music is contained above and below the staff: these details often make the difference between a vibrant performance and one that is merely correct. Many articulation marks are found above the staff: Staccato, Legato, Accents of all different shadings, and slurs. Developing a rich nuanced palate of articulation is essential for artistry! Articulation also yields clues into phrasing: following the composer's intentions and playing simply often clarifies phrase direction. Lots of directions are provided below the staff: Dynamics and other indications for style (words like dolce, agitato, etc.). THIS is where style lives: embedded in these words and symbols. It's our job to bring each detail to life and provide a solid musical interpretation. The correct rhythms and notes are all found within the staff...but the style...now that is the heart of music making. Look above and below the staff for your inspiration.