Re: need advice on improvising
I think an excellent way to work on improv is to play over all styles of music. Say, for example, you hate country. Then turn on a country music radio station and attempt to play over it. I'm not saying you necessarily have to "solo" the whole time. But add something to the song. A double-stop riff. A few bends and releases. Whatever. But make it fit the style, rhythm and feel of the piece. You learn so much about what is possible that way because the song forces you to phrase differently in order to sound decent. Then, when you go back to the styles of music you enjoy, you will have developed some new phrasing ideas that you will be able to incorporate in your improv. If we love rock and always just play over rock, our phrasing and licks etc. can remain stale and boring and never really develop much.
Other things to try are limiting yourself when soloing. Solo for an entire song on just one string. You'd be surprised how much more creative you can become when you have fewer choices. You have to become more rhythmic and work on the tone and/or dynamics of the notes. Limit yourself to just 4 notes on two strings (like the top two strings in a minor pentatonic) for the same result. It really pushes your brain to come up with new stuff and incorporate bending etc. where you normally might not put it.