I have a gravel path (actually drain rock so larger) over landscape cloth. It is only about 3 years old and I know I will have to decide if I would rather use some kind of screen/wire to hold it away from the soil in the future, but for now I have a super thin layer of the rock so moving it to replace is mostly an one day pain in the rear. I get a few weeds in the stuff that lands on the rock and ends up on the weed cloth, but not that hard to pull a few weeds here and there. The walk goes right by the house so I don't want to use bark-fear of adding more termites, the gravel is hot enough, concrete would cook us and I can't see spending money on watering lawn (besides part it is over a leech field that I don't want to add that much water too anyway) I will probably start at one end with some kind of walkable ground cover, just have not had it that high on the to-do list to start on that yet. Living in Santa Barbara, the no water cacti gardens over lava rock front yards were common. Back in the day everyone seemed to want to have one. Guess if having painful to touch lava rock was not unfriendly enough adding cacti made it better..... I can top all of your plastic bits woes. My dad LOVED using black plastic. Plastic soil bags, Yellow heavy plastic.. grocery store plastic veggie bags. Perfect for killing weeds. right. He would put something on it to weight it down so it would not blow off, but over time leaves would fall and next thing you know, the plastic was gone. So he would add a new layer. After awhile he discovered that maybe picking up old sheets of vinyl might last longer. Of course that was harder to find. Then he hit on the mother load of free material to lay down on the yard. And even better, he could lay it upside down where he wanted people to walk and it would add traction on that slippery clay. And it would not blow away. Used carpet. Fun is trying to dig through loopy strands of carpet (the backing as long since vanished for the most part leaving miles of plastic/manmade yarn for you to pull. Hitting a layer of vinyl that pulls in up small rotten squares, Just to find layers of "lasagna gardening" gone wrong with multiple plastic layers. My point is to think about what you might end up doing in the future and just how hard it will be to undo what you are working on if you change your mind.

It is hard to make any recommendations unless we know where you are. As well as the nature of the area being worked.

@sepulvd since we don't know the balance of your current planting design you can always follow your own thought, "maybe add different colors of heather". It would certainly be a safe solution since most of the textures will blend. Monocultures of one genus can be captivating.

SMC, I'm no succulent expert (just got into them about 5 years ago) but the biggest mistake I made when starting was thinking that our Florida sand would be great for growing succulents. Deserts are sand right and cactus grow in deserts, right? Well, I lived in the sandhills in Williston and my almost totally sand soil was awful for succulents. That sand wasn't loose but rather tightly packed and didn't drain well. And sucs don't like wet feet. That's why you need to mix perlite and oyster shells (or chicken grit) and light potting mix into the sand if you're putting them in the ground so the sand doesn't pack and will drain. Also, I didn't put down landscaping cloth as I wanted the plants to spread. BIG mistake as the river rocks kept sinking into the sand and I had to constantly replenish them. I could not find big rocks anywhere around me....I sure wish I had brought some with me from Ohio. So, I ended up with more of a zen river rock succulent garden. The few decent size rocks I found I gathered driving around the backroads around me house on my 4 wheeler right after they scraped the limerock roads :) I wanted a rock garden like the ones in your pics too. I had one in Ohio. But, most of those plants are cooler weather plants...more an Alpine garden. You could probably create a similar look IF you could find the rocks and Florida friendly flowering plants with a similar look and succulents. BTW...many sucs such as aloe and haworthia bloom are are very attractive to hummingbirds. Here's a few pics of the rock garden in Williston just a month after planting in 2013. When I moved in early March, the garden had filled in so much and the plants were much taller. I'm sure that it is a jungle by now without me there. Our property sat on the corner of two roads so I planted this on that corner. It was roughly 40' long and 5 feet wide. I'm almost ashamed to share the pics as it didn't turn out anything like my vision :( Female rubythroat hummingbird enjoying Soap Aloe blooms. There is a Alpine/rock garden forum on Gardenweb if you're really interested. Oh, the rock......well Joe said it was here when he bought the place. He was told that it was from the bottom of the lake across the road from us when it was dredged. I'm not sure how they ever got that thing moved into our yard LOL Rhonda