There's millions of things you can do to practice phrasing. I agree alot with _KJ as to what it actually is, but to add to that, I try to think of it (not saying I'm necessarily good at it) as similar to talking as well.
When we talk, we don't say one constant stream of words with no breaks or breaths. We break down what we say into sentences and phrases with pauses in between. When I try to home in on improving phrasing, 1 thing I do is that I become conscious of counting a certain number of notes - say, 3, then 6, then 3, then 4, then 12, etc... and playing short bursts of notes and being aware of ending my 'phrases' on a strong note (i.e. a chord tone) and add some vibrato.
That's something you can try for starters.