Well, your swords are gonna be happy with all that gravel! They have large, expansive root systems. Actually, with the right fertilization and light, they get to be HUGE, tank-busters, really!
I suggest getting a few more root plants. I really like crypts and swords for this. Place them (if small) around the sides of the tank and (if larger) in the back. They need root tabs, since that's how they absorb nutrients.
I like moss in NPTs, so try getting a nice piece of (true) hardwood drift wood like mopani and tie some java moss to it. The moss makes the tank look earthy and lovely.
Large, more mature Java ferns also provide good weight for a tank. Their rhizome cant be buried, same for anubias.
Consider getting some species of grass in your tank, too... Hairgrass and dwarf hairgrass plants add a nice carpet to sections of the tank once they send out runners. My fish like hiding in it, like ninjas. Dwarf baby tears are also nice in this way, too, but theyre not grass-like.
Stemmed plants like anacharis (which is a little hard to incorporate into a tank sometimes because it grows like mad), pennywort, water sprite, bacopa, ludwigia, wisteria, vals, etc. are good, too- and I actually think you need them when using soil (Right, OFL?), and you need LOTS, though Im not 100% sure on the reason.
Floating plants, like duckweed, frogbit, water lettuce (ooh, love this) are really good looking, too. Water sprite likes to chill at the top of the tank, too, and creates an eerie, natural look when its roots hang.
If youre doing a planted tank, get a good fertilizer! Root tabs, too, for the swords. I use Aqueon Plant food with good results (all thats around :c), but I know that Seachem Flourish and Excel are faaannntassttiicc!!!
Try creating a look that is based with a center focus... For example, get a nice piece of wood and place it in an interesting way and have the plants fill out around it. Rocks are great, too- just be sure the ones you choose dont mess with your pH.