Well, they're all a bit small... Anyway, you know how to blend the stock into the B/G quite nicely. With the exception of numbers three and five, I like them...
Click on them, they are shortcuts. Number one is nice, when you resized the render though, it is a bit out of proportion. Number's 2-5 are all very very messy. Sometimes less is more. Sharpen number 5 up some, it is very very blurry. Keep practicing, you have some very good potential.
They're not bad. I think that 1, 2, and 5 blend rather nicely. For number 3 I think giving it a little bit more of a duller green tone would help it. For number 5, the subject seems a little too large to blend the way the others do. With all of them, I'd say to not always center the subject, mixing it up a bit will be more interesting to look at. And the black borders on the top and bottom seem a bit out of place, you should either make them a bit larger to make them more intentional or get rid of them all together.
I agree with Fallen King, #1 looks nice but 2-5 look messy. It's not good to put the render in the centre of the tag every time, it can get a bit repetitive, try putting the render in different areas of the tag for a change of pace. Just wondering, are you using Photoshop or GIMP?
These are pretty good for a person who's new to sigmaking. Most of the them have some good flow but like already mentioned, some of them are a little too cluttered and it makes the composition look messy. You also stick to the center too much in your tags like Bareri said. Check out the rule of thirds. The center isn't always the most eye-catching place in a composition. The lighting should also be worked on so keep that in mind for next time.
I like number 5 the best. Number 3 and 4 though do look a bit grainy, plus there is quite a lot going on in each one. Some of the effects you use are great but just don't use them all at once. You've blended the renders in quite well and you can really see some skill and effort has gone into them. My advice would be to not blend them in so much, #2 is good but the stock is so blended in it takes the eye away from it, it's a balance that must be achieved. You do have potential so keep practicing and test out different techniques, photoshop is great for signature effects so don't be discouraged. Keep it up ^^
