Great work! ^^ I'll try to cnc, but dunno how well I'll do. :lol Don't take it harshly, please! I'm just trying to help you improve.
1)
The tag is pretty empty, to be honest. The lower lighting is a great start. Although, with the top half, you sort of messed up. Where exactly is the light source? I get the impression it's meant to be from the butterfly? Then why is the entire top part of Yato light? See what I mean? The light source on the right means the behind Yato, to the left, should be darkened with a soft brush. It looks like you tried on the scarf, but I'm not certain. Besides the lighting, there isn't really depth.
2)
This ones pretty cool! And the text is in a good spot too. Try to expand on depth a bit more by sharpening/blurring/leaving parts of the render. The text is pretty bad, too. As good a start as any.
Try to not have the text by itself, look up, for example, tiny text brushes, or something that you can but with it. Also, the text like all the same size. Try to have the top one bigger, or vice-versa.
3)
This ones pretty unique.
The text and render are working against each other. The text should be placed much closer to the render which is the focal point, in order to draw your eye to it and not try to pick between the two. The style of the text is pretty plain, but you did good with one being bigger than the other! Some basic lighting like darkening the sides and a light source would have done great here. The entire render is just basically sharpened too, which isn't what you really want. But nice work.
All in all, great effort! Try looking at more tutorials or just playing around yourself with this stuff in mind. Maybe practice just lighting on something, text on something else. Even if everything by itself, and then putting it all together.
Best of luck, mate! ^^
