There are three types of product to fill in eyebrows: eyebrow pencils, tinted eyebrow gels, and pomade which you apply with a stiff, angled brush. What you fill in your brows with is highly personal and comes down to choice:
Eyebrow gels are the best options for beginners and/or those looking to sculpt and tame eyebrows fast. They're so easy and intuitive to use, come in all kinds of shades that will match your unique brow color - clear eyebrow gel is a thing, too!
Eyebrow pencils require a bit more know how but can be mastered quickly with a little practice. Two important things to note: 1) always keep the pencil tip super-sharp and 2) never draw one continuous line along the brow—stroke the pencil onto brows to mimic tiny, individual hairs. This rule pretty much applies to all brow products—but especially pencils.
Eyebrow pomades require a bit more practice and time to learn and perfect. But when used right, they have the ability to transform eyebrows from over plucked to full, scraggly to shapely, barely-there to front and center.