Voile and sheer blinds are the in thing at present.
Why not have them remote controlled using battery operated rechargeable headrails. These hold a charge for a few months before needing to be recharged again. The charging lead is easily accessible on the headrail, hidden behind the fabric, and plugs into a phone style charger. You can even have one remote controlling multiple roller blinds or Roman blinds, and NO child safely risks !!!! as there are NO chains.
A contemporary look.
Less is more at windows, so why not go for the simple look with a hidden track and voile curtains with a wave or a double pleat heading. Keep colours neutral and then add one thing in the room to bring in an accent colour, e.g. a painting rug, or even some colourful cushions.
Why not go for a facia covered board which hides the track behind a covered fascia in the same fabric as the curtains. The curtains run along the front of the facia, very stylish and a way of hiding the track where poles are not suited. A very subtle and elegant way of dressing windows.
Whatever you decide the curtain and blind fitters at MyFitter can help you install everything.