Dlight to Sair
This is sword's B&B, most of your damage will most likely come from sair or dlight to sair, not to mention it's a great kill confirm.
Dlight to GC Nlight
Another great combo that is fairly simple that can be performed at any percent, however this is probably only best for low percents and any other time you'd be better using sair.
Dlight to Nair
In all honesty, this combo isnt really the most useful one, mainly because nair doesnt really kill all that often, and in the percent that it does kill, you'll end up killing with nearly anything else.
Dlight to Rec
This is another great kill confirm for sword if you are at the middle of the stage and not sure if sair would kill at the distance that you are. I don't recommend doing this one on a stage with a high killbox.
Dlight to Dair
This is another great B&B for sword, good for building momentum and damage. You can chase dodge after this to get better followups
The main thing you're doing with Sword is consistantly rushing down your opponent and not leaving them much time to breathe. Constantly in their face, Slight is very good and you can chase dodge Nlight for a good dodge read. Weapon Throw is very useful for sword for stopping any pressure they attempt to put on you. Sair is your best friend here as well.
Sword's Edge Guarding is insane, using dlight with it's slightly disjointed hitbox will allow you to edge guard with ease, ground pound is quite fast, but you'd be better off using weapon throw. If you don't want to take the risk of going off stage to edge guard, staying on the edge of the stage, and rotating between options like Nlight, Sair and Dlight, should easily do the job well.