The idea of an accent plant is a little dated. There needs to be some sort of focal point, but it doesn't need to be a specimen plant of any sort. It can just as easily be an open space... Creating the illusion of size in a smaller tank, or any tank for that matter, can be acheived partly by using small plants.
To maximize this effect, you would use plants with larger leaves in the front and get smaller as you work towards the rear and toward the focal point. This is only one device that you could use.
To maximize this effect, you would use plants with larger leaves in the front and get smaller as you work towards the rear and toward the focal point. This is only one device that you could use.