You have a big strong command of the trombone. I'm guessing you also have good endurance. Your intonation is solid as well. All good to have for playing the horn well.

We all have our own style of playing, and I make sure not to dictate a particular style of performing or improvising. But you use the word "smooth" in describing how you want to play. So for that, let's look at your hard articulation and forceful sound. Consider many of the trombone legends and how they approach improvisation. JJ, Carl Fontana, Watrous, McChesney... They tend toward a lighter (quieter) approach. The reason is that playing lighter - especially for brass players - allows for more dexterity and a smoother style. It's hard to run with a heavy backpack!

Again, your personal style is what feels right to you. You have a very percussive approach that is very on top of the beat. An example is the phrase at 1:20. Notice how hard you attack those notes. You might be more satisfied by playing them lighter, more legato, and a bit less on top of the beat. Think of how Slide Hapton might play that phrase: still with a big sound, but with some ghosted notes, legato and a bit laid back. His would be a more traditional swinging style. The other advantage of a lighter approach would be that you could play longer phrases that could allow you to tell more interesting 'stories.'

Trombonist to trombonist, let's talk about how you hold your slide. Your slide movement is more stiff than I think a more flexible wrist movement would provide. Why does that matter? Because just like the harder more forceful articulation I mentioned reduces flexibility, so does the more rigid wrist movement. Bob McChesney demonstrates in the samples I provide the relationship between slide movement and the perception of pitch. Watch how he sounds like he is playing a scales while moving the slide in random positions. You don't need to be multi-tonguing to get the point of his demonstration. The take-away for you should be that precise slide position is less necessary as you flow through a series of various notes. The start and end are most important and will allow an easier expression of your jazz playing.

Do you practice Rochut etudes? One benefit of them is to develop a lighter articulation and connection of notes. Even the first phrase of Rochut #1 can be a challenging exercise to play smoothly and evenly with a light attack. I recommend putting that into your practicing. As extra jazz practice credit, play that phrase starting on random notes (keys).

I don't want to discourage you, however, because there are many good things going on in your playing and within this solo. One thing I really liked was the creative way you ended the solo, using the slide as a creative device. I think if you lightened your approach in places, you could express more emotional swinging dimensions by playing longer phrases and with more dynamic variety. But you are a strong player. Keep up the good work!