Sharper images with 70-300 lens??????

[casil403]

I am having a lot of trouble getting nice and sharp shots when using the long lens ... Thing is they look pretty sharp in the camera, then when I get them home I am disappointed cuz they lack sharpness and I'm not sure what I'm doing incorrectly. I see other members shots on here who have used 70-300 lenses and they are so sharp! What are you all doing to get these great long distance shots of birds/animals that I'm not?

Anyone have comments/ideas/suggestions/thoughts/advice on how to fix this? I'd really appreciate the help...

PS...Here's some examples below....