*o* The tags you made are really nice x3 I like them c:
As you asked for cnc I will try to give some

I like the first one the best though the purple light on the girl's right is a bit too hard(?) Get rid of some of the purple on the right of the girl, its too strong and anyway I noticed the light falling on her hair is yellow not purple there so probably make the purple fractal(?) yellow or rub out parts of it. I really like how everything comes together in this one.
For the second it is good too, though the use of green in the tag doesn't make sense if you get what I mean. You have to make sense out of it by making the colour transitions smooth and in harmony with the tag. Don't just dye a c4d in one colour. =/ Make the yellow
change to green and probably a darker green continuing the cycle. Its the reason why the right side looks awesome but left side looks off. I am seeing a lot of gfx-ers lately who are making this mistake.
Other than that, the light source on the left seems a little like a wide green blank open space. I'm not good with open light spaces myself so I will just say how about adding a fractal or something over it yo make it look like it is really giving out light. Practise them a bit more and hopefully the next time the light soucre might come out perfect :3
Same goes for the third, the blue and purple don't fit in. I don't see the point in adding the colour if it isn't gonna relate to the rest of the tag. Try hinting the colour at other places or change the colours to yellowish orange you used everywhere. Also i suggest making the bottom of the tag less detailed as the tag looks too stuffy (try adding something black if that helps

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Overall all 3 of them look awesome though a bit too heavy but I probably like heavy tags. Keep it up ad you will do even better :3 And yes I know removing the colours ill make the tag look 'boring' So like I said try hinting the colours a bit here and there(like you did with purple in the first tag, a bit of it was every where) and avoid directly jumping from one colour to another if you can. ^^~