I suggest reading the All-Inclusive Guide to Texturing which is conveniently pinned to the top of this forum. It has tutorials on just about everything from getting started all the way up to advanced techniques and features. If there's something specific you're looking for and cannot find it there, feel free to ask.
As to how to do it easily... get good at art. Practice a lot. Post your work to get critiques, and learn to take constructive criticism of your work. Don't stop trying until you get good. It's going to take a lot of hard, difficult work to get to the point where things are easy. Sorry, but there's no getting around that. That's just the nature of art, any art, no matter the form it takes.
So?
I suggest reading the All-Inclusive Guide to Texturing which is conveniently pinned to the top of this forum. It has tutorials on just about everything from getting started all the way up to advanced techniques and features. If there's something specific you're looking for and cannot find it there, feel free to ask.
As to how to do it easily... get good at art. Practice a lot. Post your work to get critiques, and learn to take constructive criticism of your work. Don't stop trying until you get good. It's going to take a lot of hard, difficult work to get to the point where things are easy. Sorry, but there's no getting around that. That's just the nature of art, any art, no matter the form it takes.
I hope that helps you.