Unless you actually want to be listed on page 40 of the Google search- avoid doing these:
1. Don't abuse keywords. Using every word in the dictionary will actually ranked lower on the Google search directory.
2. Don't hide keywords. Don't think you can outsmart the search engine bot because you've "hid" your keywords in text the same color as your background. Same goes for making your keywords itty-bitty. Just. Don't. Do. It. MmmmKay?
3. Meta tag stuffing. Not cool. An example would be, let's say you had a website for cooking. An example would be creating a meta tag like this: < META NAME="KEYWORDS" CONTENT="cooking, Cooking, cooking, cooking, cooking, Recipes, cooking recipes," > Be creative and use creative keywords like: cooking, cooking crab, cooking spaghetti, paleo, recipes, diy...you get the point. One of my favorite places to find keywords is the frills SEO keyword search engine Soovle.
4. Steel other people's content. Any social media czar will tell you that quality, unique content is the best kind. Duh. Having identical content as another website won't increase your Google rank. So don't copy and paste someone else's stellar work. Think it's an interesting piece? Take the subject matter and make it your own.
5. Don't leave THAT comment. Don't be that person who leaves the lame spammy comment at the bottom of popular posts. Rather, if you really did enjoy the post, leave a thoughtful and original comment- heck even include your website address. Just don't use a spam script for thousands of forums. It's shady.