OH OK SO I recomend mostly using ibis paint and putting on the size you want for the banner (retangle in specific). If you want the @ to appear on the others follow you should also focus on the middle part since it's what will pop up most if someone clicks on "followers". You can either 1 use banners that can be used for rentry as well or 2 make it a gradient. The way you edit is for your liking :]