I can't tell you how many blogs I've visited that only use one or two tags for a blog post. And very generic ones at that! For example, if you do a blog post about a special technique for fabric flowers, be as specific as possible in your labelling. Otherwise you're just another "fabric flower" in a sea of tutorials!
Things you could include in your "fabric flower" blog post (I'm liking this topic so I'm going with it!):
Is it a tutorial? Say so!
Be specific! Colors, fabric type, embellishments...
Is it a necklace? A bracelet? A brooch? Other possible uses?
Keep it relevant!
Don't be afraid to include product names and people's names!
Think to yourself "How would I search for this blog post in Google?"
You have to remember that when you add labels to your blog posts you are literally telling the world how to find your blog.
Sure, you can add tags that have a certain meaning to you. I have my own secret (okay, not so secret since they obviously show up on the blog post) tags that I add that I use for searching my own blog. There is nothing wrong with that! But try not to use more than one of those because, really, you can find your blog a lot faster than everyone else on the planet. ;)
Let's take a look at one of my older posts, the homemade bride's survival kit. Here are the tags for that post: