Don't center your images so much
Fill your frame with your image
Ensure you have an interesting foreground that compliments your main focal point
A baby octopus is about the size of a flea at birth
Time of day can greatly affect the look and feel of your picture
Use the rules of thirds for greater visual impact
Out of focus foreground elements can sometimes be distracting
Exposure and light are the most important things to master in photography
Go look at good photos then look at your photos. You could spin around and fire of photos at random and get the same results as what you have here you have no need to be asking for c&c you just need to get a better idea of what a decent photo is.