Well, first thing, substrate, unless you are going for the garden of all gardens, it won't really matter with a single plant., if it's very fine sand you may want to add a weight to the plant.
for nutrients, a single plant should just need regular water changes (if using tap water) to replace the trace elements.
Lighting, if you are using lower light there is a limited type of plants you can choose, if your tank has daylight on it, then you're pretty much set.
was there something more you were wondering?
as for placement, pick a place that looks nice to you, remember, plants grow so try not to pin them into a tight corner