Hi. It looks a nice room. Are the blinds new as I'd be tempted to have curtains to match if the fabric still exists? You can add pattern with cushions and a throw and maybe lampshades, try pooky as they have a few patterned ones or Oka. They're also cheaper to update when you want a change! Perhaps if the seating arrangement was a little tighter you could also consider a patterned rug ( otherwise it could be a little expensive!) Hard to tell but it looks as if you can go a bit wider on the pole on the window to allow a little more light

IKEA also do some great eyelet curtains and they have some geometric patterns in the greys/neutrals and very reasonably priced.

I'd try to get Roman blinds for the bay to match the existing and only have curtains on the French doors. As Minnie says, a longer pole would be great. Inject colour with accessories. Lovely to have so many windows.

I too would try and match Roman blind for bay. As the room is quite plain make a bit of a statement with curtains for the patio doors and have matching cushion.

I would go with a Roman blind in the bay, although I have curtains in my bay and I think they look great. Shutters would also look good in the bay, but they can be expensive on such a large window. As the room is quite plain, a pattern would be good. If you like geometric then it would be a good look, especially if you choose a softer colour. Curtains needn't cost a fortune if you buy ready made, and I think that would suit the patio windows. All you have to do is move the pole up or down to match the length. Most full length ready made curtains at 90 inch drop. Good luck with your choice.

Dunelm do very reasonably priced eyelet curtains and tracks. I've recently had cream chenille and have gone across the whole wall which I think gives a more luxurious look.

You need to make a decision. Do you want the fabric to bring colour and pattern to your room or do you want to keep the whole room neutral?

If you want pattern, the next decision is what style- check or plaid, stripe, floral or geometric?

Then what colour(s). The room, as you point out, is not overly bright, but do you use this room much during the day or is it an evening room? You could opt for deep, rich colour that warms the room at night like burgundy, deep turquoise or terracotta. Adding patterned cushions with similar colours will splash colour around the room. Also, I'd replace the Roman blinds with matching fabric to the curtains, otherwise that will will lack colour. You could make a single curtain for each of those smaller windows in your main fabric and pull it to the side furthest from the fireplace, tied back.

As to style, since you don't appear to be overlooked, floor length curtains on the front window and patio doors can be on a 50mm pole extending at least 150mm plus finials each of the windows. To stack them further back extend the pole more, but take care not to have wall showing just before the window recess. Tieing them back would allow more light to come in.

Check out readymade by Montgomery https://www.montgomery.co.uk/ready-made-curtains/whitworth-21-duck-egg/9927, John Lewis (Scion Navaho), Terry's Curtains, Heals. If you choose a multi coloured pattern, later changes to your lounge will not necessarily mean that you need to change the curtains.

Remember that decorating your home is less about style and more about you and your family. Have fun.

Just blinds at the window, nothing at the patio doors but paint the wall there a fresh colour - and pick that up again in cushions, lamp shades, etc.

I know the original post is 3 years old but if you are still on here, @anita_owen it'd be good to see what you did in the