I agree on the overcast day photos. You might also try a polarizing lens to cut down on the washout from the sun.
As for the pics (you said your skin was thick...) - I'm never a fan of the photos taken within a week or two of finishing a project, unless it's a hardscape. The reason is, everything is really small, making the photographic results very underwhelming. It just looks like a bunch of little plants stuck in the dirt. Now I'm sure that in time they will grow and the beds will be beautiful, but right now they don't. Can you take pictures of work you did a year or more ago?
Another thing to consider - I see loads of landscape websites taking pictures of plants as though it was done for evidentiary or legal purposes, not to capture the beauty of the plants. The beauty that most people remember when looking at their plants is the details. So I'd recommend showing some of those. A perfect example is
Landarts' website -
LandArts: landscape designer, landscaping for Apex, Cary, Durham, Raleigh, Chapel Hill, NC you'll notice that every picture is just trying to capture a portion of that design element, not frame the whole thing. It captures the essence of the thing, and in my opinion, is far more attractive and likely to get clients oohing and aahing. You might consider going back to your projects and taking similar photos, and from different angles.
That's my $.02, for what it's worth.