The best way to improve your jazz improvisation skills is by learning and developing jazz vocabulary/language.
The best way to do this is either from etudes, transcriptions or transcribing yourself!
Check out this video I created on just how to do it!
There is NO short cut to developing jazz improvisation skills. It takes time to develop the ability to say something meaningful on your instrument.
Many, many hours are need to absorb vocabulary into your playing.
You want to be hearing things to play and NOT thinking of things to play. Don't be a copy and paste 'licks' player. They are not improvising, they are remembering.
By transcribing solos yourself, you are learning how to swing, articulate, play rhythms, play melodically (if you're listening to the right players) attack, tension and release and the list goes on and on but I think the main thing you are improving is the ability to hear what you want to play.
At first it is tricky and takes time to develop the ability to hear what someone is playing and then playing it yourself on your instrument but this is by far the best way to accelerate your ears! Try not to write anything down until you can play the solo perfectly!
Don't be too hard on yourself, it will be tricky at first but you could just try the first 8 bars, or if it's a blues, just one chorus. There will be lots of language to absorb into your playing from just one chorus.
At first, learn only 1 bar a day! At the end of the month you will be able to play an entire chorus flawlessly!
Once this is achieved it is much easier to then try and adapt what you have learnt into different keys.
Good luck with your efforts, if you stick at it you will be rewarded in many musical ways. Give it a try. I think you'll be glad you did!