Well I'm really a bad planner!! I cannot manage my practice sessions! I dunno what to practice at times and I just start doing anything and everything!! What should I do??
Don't worry about it and practice what you want to practice. I've never had a practice routine in my life but I like to think I'm a decent player...

Although it is worth noting that you should force yourself to practice things you're bad at and don't like doing a lot otherwise you'll never improve.
R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.

Quote by Master Foo
“A man who mistakes secrets for knowledge is like a man who, seeking light, hugs a candle so closely that he smothers it and burns his hand.”

Personally I think practice sessions are a stupid idea. Music is not supposed to be an exercise. Just play your instrument and enjoy it; if you want to learn or practice a new technique its better to learn a song or a piece you like that uses that technique and just play that rather than mindlessly going over scales/exercises.
Improv is also good. When I learn something new, within minutes I try to apply it in a quick improvisation, I find I learn quicker that way.
First of all you have to be sure of what you WANT. What is it that you want? Be clear with defining that. Your practice routine should be based on achieving those goals in a realistic way. Do you want to be able to play note-for-note some of the music of your favourite artists? If so, you should apportion some time to building a repertoire.

Lots of famous guitarists first started by learning their favourite songs. Paul Gilbert said he learned a lot of Van Halen pieces. Steve Vai would practice his Led Zeppelin and Jimi Hendrix, and Yngwie Malmsteen learned everything Deep Purple did. It can be a good idea if it relates to the music you want to create because it gives you a blueprint to follow for developing the specific technique that you will need to create your own music if that is what you want.

If you want to be a good improvisor, then this should be practised. Learning scales and chords and arpeggios that sound good to you is a good way for developing this. Then you can connect them and build up a bank of these kinds of patterns. Joe Satriani says learning all the modes all over the guitar is a tall order. If you haven't got that down and you want to improvise, there are books that can help with that ('Exploring Jazz Guitar', for one).

Use your ear to guide you to what sounds good and naturally you will be lead to practising those things. After all, why practice anything that doesn't sound good to you? You are the artist here and it is for you to decide and what you practice should be dictated by what you like.

Focus on things within your reach as well. You might find yourself getting bored or frustrated if what you practice takes months to just start sounding like music.

I am an obsessed planner; I have on a website everything I have practised over the last 2+ years and how much time I practised it, as well as many accompanying notes and practice schedules. If you want to check that out for ideas, you can find me here: http://www.43things.com/person/CreativeHeart
I think it's a good idea to break things up. Practice a song for a set time.. take break... practice ear training for set time... take break... practice rhythm for specific time... take break... learn theory for specific time.... etc.. it's good to take breaks. Only so much you can absorb in any given time. Shorter focused practice is better then long unfocused practice.

Well does that means its up to me how I wanna practice and what I wanna practice!