I have a few ideas that could help with the appearance of your aquarium. These are only my opinions and you don't have to agree, but I would like to share them with you. 1)
First of all, you've got a big leafy plant to the right of your tank and (I don't mean to offend) but it looks a little out of place there. The reason is because of its thickness. You've got thick decorative wood, the rocks would contribute to the thickness as well, and so does the ground sand. Now I understand that all this stuff is necessary, but it would look better if you would move the big leafy plant directly behind your crypts. and in front of your background plants. That would kind of smooth out the contrast and diminish the vividness in your aquarium just a bit: 2)
Next, you should let your ground plants grow out and cover the floor where they are planted (now I know that you might have already had all this in mind and were going to do this, but just in case). To make it look neat, keep it short and manicured like someone would keep their lawn (with scissors in stead of a lawn mower of course) 3)
Also, those nice long stem plants next to the big leafy plant could be moved directly behind the spot that I suggested you move the big leafy plant (sorry, I know this is worded a bit weirdly). This would make a group of nice long stem plants that need to be organized a bit and, but you decide the way you would like to do that and my one suggestion about this is to spread them out a little and give them room to breathe: 4)
Another improvement would be to move the anubias to the places where I have marked with an "X". This would give your aquarium a more natural look: 5)
Lastly, I would put white background or something to cover up the big black thing in the back of your aquarium.
~Katie (Daniil's daughter)