You have been to some great places and have some nice images, but since you asked for opinions, here are my thoughts on a number of ways you could improve your landscapes.
* Apart from the first couple, they are all taken in quiet harsh light. I know you can't always be somewhere at the right time but being out in the "golden hour" just after dawn and just before dusk will dramatically improve your images. In photography, light is everything.
* I find most of the images too balanced around the centre, the tree at sunset smack in the middle, the gorge right in the middle and the stromatolites evenly balanced around the middle. That's why I prefer the river image as I think it is the best framed (composed) image of the lot. Have you heard of the "rule of thirds" which breaks the image up into thirds along the horizontal and vertical axis. For most images if you frame them according to this rule it will make your images much more interesting and dynamic (however rules are made to be broken on occassions!) Also the river image has a nice leading line, the diagonal created by the river which helps to lead you into the image.
* Have a look at your horizons. As well as being level(not in shark bay), they should generally have one third land and two thirds sky or the other way round. Usually avoid putting the horizon halfway like in shark bay. Many of your images have just a little sliver of sky or of land...it's not enough. Decide which is more interesting and go with that. Or just take the sky or just the land, no need to have a bit of each in a photo. In some of the images (river, gorge and flowers) the sky is completely featureless. That's often just the way it is in these areas but perhaps you could get some more colour into it by underexposing a little or using a polariser or some careful adjustments in photoshop. Keep an eye on your cameras histogram when shooting and make sure you keep all the detail in the clouds.
* Would be interesting to see the original uncropped images and see why you chose to crop the images as you have done. Have you experimented with stitching images together for panoramas.
* Just because you are shooting landscapes doesn't mean you always have to shoot in landscape format, try some in portrait format as well.
* I would be inclined to punch up the colours a little and give them a little more oomph as I think they are lacking a little due to the harsh light.
* Remove things (not physically, but either by reframing or in photoshop) like the survey post and tripod handle/wing mirror(?) in the flower shot.
Just my thoughts anyhow, hope they are of some help. I just want to crawl down into that gorge and go exploring, looks fantastic!
