I really like the pens. The trick with the pens is to start with a lighter shade than you think, and try it out. If it's too light, it'll look like you didn't spot it at all. If you put too much on, or too dark a shade, then a quick dab with something wet (a q-tip in distilled water is probably best, but I've been known to wet my finger with a dab of spit as well) will take it up immediately to no ill effect. Best technique is to hold the pen vertically, and dab downward (as previously mentioned, think pointilism). Don't try to use it like a pen to draw lines.