OK there is a fair bit going on here...
Plot:
i.imgur.com/GXcV0Ds.jpg. Looks good from above but you can use the island background and get rid of the mainland if you're looking for an island plot.
Clubhouse:
i.imgur.com/rHcGhx3.jpg. Good looking clubhouse sitting up on top of the hill. I like the flowers, did you want to put them into a planter box, or are they wildflowers?
Clubhouse terrace:
i.imgur.com/ONdEyuv.jpg. Might want to fatten off the terrace before you loose a patron into the water.
1st tee:
i.imgur.com/EAisbpo.jpg. I'm wondering how the mower made the cross patterns through the fence. Also the hole marker in front of the back tees is a little distracting and I'd be worried about hitting it.
1st fairway:
i.imgur.com/mOS59Pw.jpg. The mound in front of the green is excessive and I can't see the pin. There is also wild grass growing on the fairway, surely the mower would have cut this.
1st fairway:
i.imgur.com/ZrxjVui.jpg1st green:
i.imgur.com/4AoS9Bg.jpg With such a high mound beside the green my view was restricted.
2nd fairway:
i.imgur.com/BkYFqkn.jpg Some additional smoothing so I can see the green.
2nd fairway:
i.imgur.com/BfHZ6IJ.jpg2nd green:
i.imgur.com/lg7IXIt.jpg Difficult to make a putt through the rough to the correct tier.
2nd green:
i.imgur.com/wMbK7pg.jpg3rd green:
i.imgur.com/HpjxpqD.jpg The green seems violently sculpted and you'd struggle to get near the pin from the wrong tier. The bunker needs additional sculpting.
4th tee:
i.imgur.com/oPtiFhf.jpg. The red trees look a little spam planted. Try to vary their height and rotate them a little further apart to give them a more natural look.
5th green:
i.imgur.com/QdSexCi.jpg Need to tone down the sculpting on the green.
6th fairway:
i.imgur.com/LWPaSDT.jpg I hit a great drive down the middle and now have a tree in the way.
8th green:
i.imgur.com/Bctapnf.jpg Bunker behind the green looks like it wants to eat people, I'd hate to go in there.
9th green:
i.imgur.com/k64X3vl.jpg Aggressive hill behind the green would be hard to mow.
12th tee:
i.imgur.com/F9RYEfU.jpg Floating water in the background.
15th green:
i.imgur.com/r9vN1fL.jpg A wild green with some very furry bushes covering the hill. There are a couple of pieces of fairway bleeding through the front and right side of the green.
17th hole: Why would I hit the black line when it's closer to straight at the hole.
18th green:
i.imgur.com/5CkgsZW.jpg A very wild green that would require a lot of divot repairs from the amount of chipping from wrong section.
So some additional smoothing out of excessive slopes on the fairways and greens.
Watch the transition to green surfaces.
Make sure the greens can be mowed and no slopes are too severe around the edges.
Smoothing and sculpting of bunkers.
I hope these suggestions help.