It is a tricky question Bades, because there are so many aspects wrapped up in design. Certainly learning to use the software is a part of learning, but there are many more aspects to good design that are independent of a computer.
If you want to hone your craft I would start by reading anything that interests you and take note of those things you really like. Some people love working with illustrations but aren't so fussed on Photoshop work. Others are the complete reverse. Others like to be familiar with both and use them together.
You are right though that practice can only take you so far. Real world experience is where the tools of the trade meet the harsh reality of deadlines, complaints, restraints, budgets and boards. (Sounds appealing right?). If you want to get some experience ask around your friends and make yourself available for some freelance work. Work with charities and mock up products for them, logos, letterheads. Treat it like a real job and take the time to learn as you go. There will be no shortage of sports clubs, community groups etc that would love to use your current skills. Offer them a few hours for free.
Here at the office we often get approached by new grads. Their portfolios are great and full of wonderful examples of what they've done. But often they lack the speed of being tied to a deadline with a budget. Or they lack the refinement of a client's demands to use only 3 colours. Design is a fantastic craft but it rarely operates in a vacuum. There are few people who get to work at the top tiers where the magic of endless revisions can occur.
There are tons of ways to improve your design, but ultimately unless you have some goal you are working towards there is no incentive to do endless tutorials.
One of the simple ways I improved my photography was by reading art books on perspective. Don't be averse to trying avenues you may not think have immediate relevance.