I agree with the other suggestions. I would add that to me, and this is just opinion, but the lighting looks quite flat resulting in images lacking a sense of dimension and proportion. Even just using natural light, a single reflector as well as a shade would let you control the light better, thus creating the shadows needed for that sense of dimension. Or use what is available, the shade of a tree, a wall or building...anything handy...
#2 really has potential to me, the composition and pose in #4 also has potential yet also is the perfect example of what I call flat lighting...there are no shadows to create a sense of dimension. If that makes any sense?
Your final shot again to me had potential, had more shadow to add some depth, but overall, to be honest the lighting is just not what I think you had in your mind's eye when envisioning the shot. I sense what others have suggested already, the perspective is sorta off and almost uncomfortable, and not in a good way, to me as a viewer of the shots.
As bad as that sounds, nothing a bit more practice can't help. Patience in setting up the shot...better one great shot than a dozen mediocre or worse shots....and still I would say very nice effort!! I do see you had a plan of sorts...can't wait to see more as time goes on!...btw they are still better than 99% of my portrait shots, I just don't have the patience it takes. I like candids and such over posed shooting. Ironically I LOVE still life/product sorta shots though. Dar-field, bright-field and other similar techniques...I find they migrate well into other types of shots.
BTW, I REALLY like the pose here
Old Town Portrait 8 by ~LytestylePhotography on deviantART but the crop is way to tight...it has a great feel and she has a wonderful smile. It even shows in her eyes that it's a genuine happy smile (even if it might not have been it looks like it is to me.)
This one
Stone Archway by ~LytestylePhotography on deviantART I REALLY like and thing with a bit of either PP or even a touch of HDR it would be a very interesting shot!! I know it is just an archway/door sort of thing but ya got the textures, the light differences plus other things I dunno how to explain...super shot to me anyway...btw, I would clone out the bench as well as the shadow from that pole across the brick on the patio on the other side before anything else.
For sure do not be discouraged...there are some really nice shots in your gallery!!