a good tag has 3 things: style, blending, and legibility.
the style has to be uniques, the letters have to comebine but still flow, and you have to be able to read it. to get a good tag, you have to pratice it until its perfect and if you dont like it than START OVER. go on youtube and type in graffiti tags watch every video you can and take notes. by that i mean practice writing other peoples tags. this will make you fimiliar with tagging. also look at comments to see what other people are saying. the tag is the most imporant part of graffiti b/c its how graffiti started
this is a good website but remember that letters need to blend for a good tag. so copy then modify it til it looks good. practice it for a month and if you still like it than keep it