Hey Richiie - thanks for your feedback. Glad to hear that
That's a very good question. Once you know the tools which you can use how to make it sound nice and melodical ? There are several steps possible :
Learn some jazz themes and check out how melodies are formed and compare it with your knowledge of theory and learn how those melodies work and then try to make variations of those melodies. Start with simple themes such as " St. Loius Blues " or " Take the A Train " . Sometimes there are gaps in the theoretical knowledge who don't cover all of it - just take it as a challenge.
The other thing is - work out your own melodies and try to move from chord note ( root, triad, fifth ) to chord note. Try to avoid to stop too many melodies on the root note or only when the melodie is an ending. The root note sounds a bit boring - try to listen how the triad or the fifth sounds and try to get inspired. In Jazz you don't need to play many notes - just the right ones. That's a good tip. Your ears are the guidling line to select.
That would be the best advice if you are still in the basic jazz improvisation level.
If you are more experienced you might want to work with " options " in your melody making. There you target the remaining notes execpt the chord notes in your melody creation. You find some theory written about this here :
I hope this helps for a first improvment