Start with one thing. Don’t start with many options or you’ll be paralyzed by the paradox of choice. Start with one font family, one font size, one color. Add your content, and figure out what needs to stand out. Add just one thing to emphasize. Like one more bigger font size for headlines.
Only add one more if you truly need to. Have a reason to add one more. But most importantly constrain yourself to starting with one variable—one font size, one color, one font family. Make sure the content tells you what to emphasize. Add one from there. If everything stands out, nothing does. Start with one and add to it from there. Adding is easier than reducing.