Actually, I don't have one. After you achieve a level of proficiency, for the most part you can simply maintain it by playing. Well, okay, I don't always do that. If I don't play for a few weeks (or months), I've gotta sit down and focus for a while to get things moving again. That's not really a routine, though. But there was a time... hmmm. Let me tell you about my practice routine back in the 'olden' days. I must warn you, though, it ain't pretty. Maybe you like to have things organized. Maybe you want someone to tell you, "Play scales for 15 minutes to warm up, then work on a song for 15 minutes, then practice lead for 30 minutes, then practice looking cool in front of a full length mirror for 10 minutes, then go down to the bar for 10 minutes, come back and finish up with another song." Well, I can't stand it!
I have always practiced whatever I felt like pursuing at the moment. In fact, I would say that I never even have any sort of "routine," although I do tend to practice certain things in certain ways. Such as: I might compose and record some songs. I always had this uncanny knack for composing stuff that was just a little too hard for me to play! So this always made for a good set of exercises.
If I felt really patient that day, I might play up and down through different scales in different keys, sequencing them improvisationally. Practice clean for awhile, then change it over to distortion. Maybe playing some classical pieces to the 'clicker.'
Play in one style, then switch gears and play in a different style. Or play some major-type scales after doing a lot of minor-type scales. (That is, play something with an opposing feel, but still within the same mode of practice).
Get out a metronome and get detailed, working up individual patterns for pure speed and accuracy. (Both clean and then distorted. ) Usually I'd just pick a few at random out of Speed Mechanics, then make up some variations on them. (You can work out of any of the books, of course).
Take a difficult classical piece that I already know fairly well, play up to the first trouble spot, then stop, isolate the difficulties, create exercises and variations that work them out, then go back and try that difficult phrase up to speed. Then I move on to the next hard part, doing this again and again until finally I have to whole thing down pat, exactly the way I want it.
Run through an entire piece, or song or whatever, just like it is performance: no stopping allowed. You could call this "performance practicing." (An opposite approach for the one just previous). Pull out a brand new piece of music, reading and learning it from scratch. Slowly. Jam over rhythm tracks, improvising leads. I probably never did enough of this... sure is fun, though.
Stop and pet my cat... She can be pretty demanding. (Actually Sabe is gone now. RIP)
Let a blank cassette roll and play whatever comes to mind -- a creativity exercise. Usually this would be riffs and song ideas, which I'd later listen to, picking out the good stuff to write tunes with. Arrange previously recorded ideas into "trial arrangements," lay down a drum track with my drum machine and then lay down some guitar and bass tracks, then set these aside to decide later what they might be good for.
Pull out the special, top-secret practice techniques (when I'm certain no one is listening) to gain superhero powers! Beyond those imaginable by ordinary mortals!! And... Oops, the secret's out... forget I said that. Play with the band. If you're not in a band already, get into one, or at least start jamming with your friends. Performance practice. Play through songs or pieces as a dry run, without stopping for anything, as if you are 'under the spotlight' before millions of crazed fans!
And maybe a few other things that I can't think of just right now. You should recognize that the purpose of most of the above approaches may be a little different than what you may need at this stage of your development. As a general rule: Start with a book/CD method that suits your current level and area of interest. (I've already incorporated a lot of variety into their very structure). Then learn some songs from outside my methods: whatever inspires you. To this basic repertoire of material, pick one or two to the above approaches and add it into your practice routine as well. Then add other approaches, one at a time, and see what works out for you. As you evolve your own routine, trust your own instincts.
Of course, my list is by no means complete. Compile your own list -- if you need a list -- and add to it whenever you come across something interesting. If you must, you can assign time amounts to each part of your practice. (In which case, I'll give you a suspicious, sideways glance). Or maybe you prefer the freedom of having no structured schedule. (In which case, you get an affirmative nod. )
There are two kinds of people in the world: the organized and the disorganized. I know I'm organized somewhere deep down, but I apologize for it sincerely and reject it wholeheartedly, preferring the intrigue of chaotic, reckless abandon. That's the way I like it. Maybe you like it that way, too. Or maybe you're a guitar Nazi. Or worse yet, an accountant! But seriously, the point here is to take freely from my list and evolve your own practice routine. Do what works for you.
Footnote: Perhaps the reason I never had to organize myself all that much as far as practice, was because in the course of teaching and writing I was doing way too much organizing already. Teaching is a great way to keep reinforcing all the details like scale patterns, theory, etc. -- I mean, after you've taught your 357th harmonic minor scale, it's pretty well burned in there! Plus, over time learning hundreds of songs on the spot, by ear, has to do something for you, too. So don't take my anti-discipline theory too seriously.