Cascading effects are what you are looking for
You have nice stem plants in the back that's great. They could be allowed ot grow denser and really form a dense back ground
I'd move those crypts in tighter in front of your tall stem plants. You can even use some creative dragon stone and or driftwood to separate plant sections and help give that cascading layering levels. Then in front of your tall stems and your medium mid ground plants search out some low growing plants for up front.. You can even do some creative stone and driftwood layers up front, or create a zen stone garden etc... doesn't have to be plants just has to have that nice small to tall look IMO
But making your tank a little more dense and really giving your tank that feeling of depth with small to tall plants is what most eye catching aquascapes share in common.
NOTE: More density more plants requires excellent water flow. Not sure of your light and Co2 setups but that also come into play with what type of plants you will select.
Google is your friend for inspiration.. as is the home page of aquarium advice . they have numerous tanks with write ups for you to peruse
And more reds and whatever colors you can wiggle in will help. Again there is also plenty of interesting natural stones to consider here