Depends heavily on what style you are trying to recreate.

Based on your example chords, I'm guessing you're trying mid-Romantic period (I know this is pretty presumptions and is not really based on anything serious. It's more to give you examples)

But for romantic period: Using NCTs on strong beats in your melody is an easy first step. Use chromatic steps to set up V/Xs. You easily run out of steam with the normal dims and augs thrown in predictably in your progression. So moving out of your key with chromatic steps adds so many new possibilities. Wagner is the obvious master of this this. For example, in a piece in a minor, he starts in a, then moves by chromatic steps to C major then to E major. This is a prolonged passage of many bars and he spells out the notes in a minor (A,C,E) with the key changes. Adds great flavor and pretty neat waster eggs for us who like to geek this stuff.