I have a healthy obsession with eyebrows. Everyone who knows me knows that. I will shape anybodies eyebrows if they let me. I have my grooming kit on me at all times since I also do this at my part time job.
The debate has always stood. "Powder or Pencil"? I myself will always add a little of both. While I do love naturally worn eyebrows with no powder and/or pencil, I think a little enhancement goes a long way.
I used to only use a dark brown powder. I found that the only way the powder would stay on was if you either applied lotion or foundation to the eyebrow area first. It just never stuck well without the proper base. Even if you have oily skin, I saw that the foundation and the oil were making the powder look somewhat cakey.
I then went into the pencil faze but I found that with the pencil, it looked a little heavy and overdone, even with the attempt at the lightest strokes. The problem was really finding the perfect base and a balance of BOTH pencil and powder. Powder to fill in the gaps, and the pencil to define.
After years, I recently discovered Urban Decay's primer potion. After I put on my tinted moisturizer, I would wipe my eyebrows with a cotton ball to remove any product that might have been on the hair. I then take the primer potion, wipe the product onto the tip of my finger (you should never double dip with the wand, the potion will get dirty if you put the actual applicator onto the skin) and put all in and around my eyebrow. This should be a very small amount. The primer potion to my knowledge was made as an eyeshadow base. Well, I just so happen to use a medium-dark brown eyeshadow. It mattifies the skin around the eye, conditions it, and sets the perfect base for the shadow in the brow. If you have any spareness in your brow, or bald spot, then this trick is just for you.
I finish off the brow by connecting the hairs under the brow in the way that they are growing. This makes the shape more defined and connects the hairs perfectly. I also like to elongate the end of the brow.
Photo is of my finished brow :) Good luck!