D'Addario Woodwinds Blog: Tim Price Bloggin' For D'Addario Woodwinds- a organized way to approach transcribing.

Following is a step by step, organized way to approach transcribing.
TRANSCRIBING

1. Begin with short forms, simple solos. Prez < Lester Young > is a perfect starting player to study.
2. Look for a tune for which you know the progression when possible, or try to find the progression in good legal fake book.
3. Check your turntable/cassette deck with a piano or tuner to assure proper pitch and key.
4. Tape your selection in order to make re-listen- ing to a particular phrase easier to do.
5. Re-play problem (or fast) passages at 1/2 speed (7 1/2 to 3 3/4 IPS on tape or 33 to 16 1/2 on a turntable). This lowers the pitch one octave and reduces the tempo.
6. It is best to use your own instrument to transcribe with, rather than a piano (unless you are a pianist). It is sometimes helpful to use a piano to solve questions about the harmony.
7. On a sheet of manuscript paper, mark off the number of measures (using double bars to delineate sections if you desire) and write the chord changes above the measures. Use slash marks to indicate where chords fall in measures where there are two or more chords. During this process you should be listening to become aware of the form of the tune, identifying "guideposts" (number of bars in each section, recurring rhythmic figures, recurring phrase patterns, etc.) which might help you as you progress to the "note by note" process of the transcription.

8. On a separate sheet of paper begin your transcription of the solo line. Begin by putting the pitches in each measure or phrase using only note heads; fill in the beams and stems (rhythms) after completion of each few bars.
Be sure to refer back to your chord/form sheet ,knowledge of the harmony might be helpful in identifying " not heard pitches" in the solo line.
9. If you encounter problems in identifying the pitches in order.Many times, identifying the more easily heard pitches in a measure or phrase will make the mystery notes easier to find.
10. Play back phrases or sections at regular speed to check for accuracy; play along with the recording.
11. Play along with the whole solo as much as you can, without the music. If you have used your own instrument to transcribe the solo you will be surprised at how easy it is to play the solo from memory.