Hey there!
I think you need to work on your composition. While the shots don't look bad per se, they at least look a little bit too random for my taste.
Number one is all tilted, you should try to get the photographs more or less strait or at least make the onlooker realize, why you chose to tilt it.
Number two just doesn't focus on anything, there are a few violet flowers and a lot of green around, but there is no real main central feature the eye is drawn to.
Number three might have worked, if you had chosen the depth of field correctly. I'd have taken it all into focus with a smaller aperture. It might have made for a good still life then. I know you did it on purpose that way, I just don't think it works very well.
For number four goes the same as for number three, there is simply too much out of focus for my taste, plus the motive just isn't too spectacular.
Well, I hope this helps a little!
Sebastian