Well done on getting back to photography.
1: IMO a centered crop doesn't work - a thought would have been to take the picture down the length of the log with only the pine cone in focus.
2. Not bad but I think the sea/sky needs some jazzing up ie a setting/rising sun maybe.
3. I like the bluebottle although, as the other comment said, maybe cropped too close to the left
4 Not sure what story this is telling me - the tank bottom left is also messy as is the rope
5 I like the leaf although could you crop it to fit in with the rule of thirds
Have a look at these: