Of course you can protect your work with a copyright notice. And you can take the additional step and protect it with the U.S. Government, so you can sue a violator not only for use, but for damages. (You can’t sue for damages unless you register your work.)
Giving credit openly and freely would make most copyright unnecessary. Giving credit is not a boring obligation, it is a smart way to get your name known. To be more visible on the internet. Giving credit makes you look smart, but even better, helpful.
How does it work? Simple. When you use a photo from Flickr, Creative Commons (following their rules first), or mention a book, a quote, or an idea that is not yours, tell your readers where it came from. And not just whose work it is, but where you found it. For example, if you find an image of Klimt’s on a website by butterycrumpets (on Let’s Draw Sherlock!, for example) it becomes a different story than if you find a Kimt image on Wikipedia. The context is different, and the story you have to tell about it is different.
Context changes emotions and opinions, and when you leave breadcrumbs for people to follow, you open up a whole new path for people who are curious and interested in more than knowing where to take the next Kimt image from.
When you give credit, you become the person in charge of information, and people will think of you as a good resource. (Not a bad way to be thought of.)
When you give credit, you also share information, and as Annie Dillard warns, “Similarly, the impulse to keep to yourself what you have learned is not only shameful, it is destructive. Anything you do not give freely and abundantly becomes lost to you. You open your safe and find ashes.”
― Annie Dillard, The Writing Life
Giving credit makes you look generous. That includes techniques you learn in a class, ideas you came up with (but find that others share, too), and shortcuts that make you look smart.
Why share? Because it makes the world more interesting, more expansive, and encourages other people to share your ideas and class tips. And to quote Annie Dillard again (Goodreads is wonderful for finding quotes):
“There is always the temptation in life to diddle around making itsy-bitsy friends and meals and journeys for years on end. It is all so self conscience, so apparently moral…But I won’t have it. The world is wilder than that in all directions, more dangerous…more extravagant and bright. We are…raising tomatoes when we should be raising Cain, or Lazarus.” ― Annie Dillard
––Quinn McDonald is surprised how many people think clutching information to their chest is a way to become smarter. Every teacher knows that you learn by teaching.