so, let's talk about eyebrow pencils. They are a makeup product which I use up quickly - second only to mascara. I've gone back and forth between MAC eyebrow pencil in Fling ($19) and Clinique Superfine Liner for brows in Soft Blonde ($18). Both are ashy, muted colours which look natural against my fair colouring and ashy blonde hair. Here are some images:
Now, the reality is that these products are very similar. They are both precise in their application, not too powdery or hard, and natural (on me) in tone. Both contain little product and get used up quite quickly. The lasting power seems good to me, but since I go for a natural application I might have a less clear take on that than someone who goes for a more dramatic look. I would recommend either, though if you're on a budget recognize that since you'll be buying these frequently the cost will be a factor.
If you're just getting started with eyebrow pencils, go with a nice light shade and stick to the natural shape of your brow. Either the Clinique or the MAC would serve you well. Having polished brows makes a surprisingly big impact on your look - especially if you are going to have your photo taken. If you're a blondie like me, filling in your brows can help you avoid the disappearing features effect. Think of this product as mascara for brows: it helps define and frame!