@VioletRed First, I like your landscaping :D and second, why does your terrain paint look so different to mine??? Your grass texture looks so good *sobs with jealousy*
Anyway, lets start.
I found some items sticking through eachother. Pay attention to that.
http://i.imgur.com/3qN2njO.jpg
http://i.imgur.com/BwVtPAr.jpg
You also need to make sure to playtest, the gras didn't let my Sim enter the pool. Deleting one or two solves that.
http://i.imgur.com/UMJmLXy.jpg
I noticed the hedge in the corners had a different size. If that was intended I apologize, but it felt weird.
http://i.imgur.com/mzZuI2w.jpg
You have a great natural pond, and I like the creative use of those potted wall flowers. But to give the pool a more natural look add some natural walls and floor to it.
http://i.imgur.com/mBLx0Bp.jpg
http://i.imgur.com/4zl7Gp5.jpg
I gave this tip most people so far, add some earthy terrain paint below plants and arears Sims use alot. This looks more natural.
http://i.imgur.com/qZAetpk.jpg
And the last thing are the trees at the front. The pot they are in somehow feels out of place. I suggest hidding it in a basement room or use something else.
http://i.imgur.com/7KMq1NE.jpg
http://i.imgur.com/1tTyOCR.jpg
That's it from me. I think @Cbear13 might find more.
