This is mostly a problem for people who dye their hair. You dye your hair auburn and you buy an auburn eyebrow pencil. You bleach your hair and you think that your eyebrows must now be bleached. You do not need to match your eyebrow and hair color to looks good! You just have to pick a shade of brown with a slight tint that goes with your hair color and it is usually your best bet.
Eyebrows with hairs sparse enough to let the skin underneath show could be overly softening your features or just looking straight up messy. Invest in an eyebrow pencil in an appropriate shade. Filled up your brow!
Do not lay your brow too thick! It looks like your brows are painted on, for one thing. And it’s probably drowning out the rest of your face. Use light, short strokes instead of pressing down or dragging lines all the way across. It’s easier to control what you’re doing that way.
Always make your brows after you’ve put on foundation and/or blush. You’re doing brows for a different complexion if you do them before any of that. Make coloring/filling in your brows one of the very last steps in whatever makeup routine you do. That way it will match the rest of your face better!