I know the challenges are different for everyone. What are your challenges? Knowing what to practice? Lack of a teacher? Motivation? Inspiration?

As a teacher and a student, I'm continuously trying to get to the bottom of this.

http://webaom.com/blog

For me its getting out of the tried true licks strung together with scale notes. Finding musical statements that are unique is quite a challenge. Almost every lick I know came from either another artist or book. Finding something that sounds unique is hard!

you have to have something to say to be able to improvise.
otherwise you'll end up with only empty notes.

Ultimately, I want to play what I hear in my head. Spent years filling my head with as much theory, arpeggios, chord construction, licks, modes, etc, which give my the ability hear the sounds in my head and know how to translate them to the instrument. Then you spend time at the application aspects of playing which is practice practice practice with lots of repetition.

You can approach each phrase from several angles (chord notes, scale or mode, relative arpeggios, etc) but really need to hear it in your head to make it successful. The real trick is to allow a free flow from brain to fingers: you need to trust yourself or you just fall back onto common patterns or stolen riffs. If you can whistle or hum an interesting passage over the chords, you should be able to put it down on the instrument; if you can't come up with anything, you need to fill up with the stuff I listed in the first paragraph. Oh yeah, and listen to lots of music...really listen to it and try to interact with it in a way that it becomes part of your musical lexicon.

Music is a communicative form and the more words, languages, grammatical rules and styles you can draw upon, the more successful you can express what you truly feel like saying.

Lastly, give each note a valid reason to be played.


Edit: sorry, I misread the question but I will leave in my pedantic patter because it took so long to type.
My biggest challenge right now is getting my technical proficiency on the piano up to the level that it can play I hear.

No worries, thanks for your insight. I love to hear how different people approach improv and how so many people can think about the same thing in so many different ways. Cheers.

"What are your biggest challenges when learning to improvise?"

Improvising shall always be a learning process, for me.
A way to enter in to sound, music and being in a profound way, and like life, can have any number of challenges.

I've always approached piano improvisation through quiet abandonment and heightened focus.... listening, feeling, playing, drawing upon experience, reaching forth in to unknown territory
consciously
in wild play.

I approach improv (both personally and when teaching) through a chord structure. I call it "getting off the sheet music." It's tough for many people to make the transition, but by doing so, I believe true musical authenticity can be expressed and heard.

As trained pianists, our brains will translate to our fingers all the skills we have learned through playing sheet music, but in a much more expressive way as we use chords for the foundation.

I love hearing students play this way because it shows their creativity. It's very rewarding as a teacher to see their learned skills mingle with their imagination!

I also don't think that improv can be practiced because if its truly improv, how could you ever repeat it? Practice "getting off the sheet music" instead.

Learning what to leave out.

I agree with Daviel.
My ego wants me to achieve more and more.
Whereas if I concentrate on mastering one little bit of the process chunk by chunk, the results should ensue. This is, I believe, the essence of Bill Evans' inspiring tutorial movie that was posted by venice last year.

I am one who has always played from sheet music (when I learned to play as a youngster). I've only just returned to piano after 35-40 years and find that I still have a good knowledge of most chords, and I want to learn to improvise.

You're right that it's a very tough transition to "get off of the sheet music." Could you elaborate on how/where to start in this process?

Thanks!

Start listening [more] (to jazz and improvised music) and just start playing, one embellished or improvised note at a time. If you can afford it, quality instruction from an experienced teacher is invaluable.

Dave Frank is a respected jazz educator and world class player. He is regularly on this forum, and has a long list of instruction videos. Get into them and do what Dave Frank says. Joy of Improvisation thread.

*sobs*

For me, the largest problem is maintaining a steady beat in the left hand and being able to play what I want with the right hand.

My improvisation was lame until I started singing along with it. There's something about singing along with improvisation that makes it more melodic and interesting. It helps make the brain-finger connection. At the very least it helps with phrasing because you have to stop and take a breath on a regular basis.

Letting loose while focusing on being melodic.

concentration, energy and motivation

As pretty much of a beginning improvisor, I'd say it's important to keep to a slow practice tempo. Once you start to speed up, you're learning to play what you already know faster, but are much less able to think - "what if I try this or that?".

Two things:
First challenge- actually liking what I'm trying to improvise (it usually doesn't sound good)
Second challenge- When I actually like what I'm improvising, I lose control of my body and get "too into it" (then mess up). I feel like alot of jazz improvisers are just jamming so hard, but can contain it so well that it looks so calm and pristine.

here's a good example:
https://www.youtube.com/watch?v=30RrATHPVtk

(1:52 on)

that's an amazing performance by John Lewis. I want to be him when I grow up.

I don't listen to the note I just played tell me what note to play next.

Yes, he's such an inspiration. Him and Billy Taylor both actually. John Lewis's style is so matriculate and reserved.
If anyone said "what's jazz piano?", I would instantly mention his name

Right now I can play some scales and arpeggios over chords. My biggest challenge is to make it sound any good

Keeping the voices in my head! ...My approach right now is very much tied to singing. The challenge is not to get too influenced by the changes I play, if that makes any sense.

When I'm away from the piano I sing/scat over any tune and find myself being overly creative. Then comes the time for me to sit and play them...and wosh they disappear. Maybe it has to do with my lack of experience.

I find it helpful to record myself and codify the concepts on the piano, but that's hardly improvisation?