Practice does not, in fact, make perfect. It doesn't matter how much you practice if you are doing it wrong. You will play the way you practice, so practice makes permanent. As it turns out, learning how to practice is the key to learning music.
There are many misconceptions about this. I hear parents telling their children that they need to practice for 30 minutes every day. That's a good goal, but I only gave the kid about five minutes of work to do and after he's done it twice you are going to have 20 minutes of fidgeting, messing around, and repeatedly asking, "Is it time yet?"
One of the most destructive phrases in the early stages is, "Practice this until it sounds better". That is non-information disguised as a goal. "Sounds better" than what? "Practice" how? I realized early on that if I'm not teaching someone how to practice then I'm not teaching them how to play. I sometimes fall down on the job. When someone with past musical experience comes to me, I assume that they already know how to practice. Of course that's not always the case.
The first lesson on practicing usually begins with some variation of the phrase "this is going to take some work". In theory most people understand that. But in reality they are often surprised that success is less about natural ability and more about consistent effort. (Insert Aesop's "The Tortoise and the Hare" here.) And I like my students to start off slow and have some early success. We can work our way up to 30 or more minutes each day.
Not all work seems like work of course. I have a friend who loves to garden and is always talking about planting, weeding, or harvesting. I would rather buy some genetically modified veggies at the market. Or, if I'm feeling particularly rustic, stop by the farmers market once a week. Another friend likes working on cars. His hands are always dirty and sporting a new wound or two. And when he talks about the problems he solved he sounds poetic. Or he would if I knew what the heck he was talking about.
These are things they enjoy doing. The results are well worth the effort to them. The amount of effort required does not count as work. Me? I would prefer to jump in my car to drive to the store and buy food that's ready to eat so I can get back to practicing my guitar. That sounds perfect.