Solo Entrances
I was browsing through Hal Cook’s How to Improvise (Advance Music, 1991), a great resource for the jazz student, and came across this piece of advice (on p. 18, if you have the book) about starting a solo, which resonated with me and, I thought, maybe would with you:
Focus on holding back your entrances, i.e., play on your second or third impulse to play rather than on your first. Notice that you could play at any time but are consciously choosing to wait until exactly the right time. Then, when you decide the time is right, release the playing purposely, with conviction. The release can be either loud or soft, active or inactive, but is should always be definite and controlled. This approach helps to develop concentration and infuse your playing with spirit and  character. (Emphasis in original.)
