I agree MikeSudomaPhoto, empty space tends to draw the viewers eye away from the main focus or point of the image to much, try to find some leading lines in your image to draw people into the picture and make them feel they are there in the picture. You've got some great pictures there to!
Thanks Scoobs, I agree with you fully on leading lines! It's awesome when theres a person or something interesting that the lines lead unto. It rewards the eyes a little bit.