For your last signature, the edges seem very jagged and blocky for the hair and the left wisp on the feather. The jaggedness can not really be avoided if you choose to use .gif format, but you can certainly go over the image again and help it not look so blocky so when you apply a border, it is not so obtrusive.

Try .png next time; it will allow not only for transparency, but several opacities as well. It does mean a larger filesize, however.