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Beautiful Room!

1. FIRST thing first, move that wardrobe to the empty wall and away from the bed. The bed is supposed to let you breathe and rest. You dont want to wake up or stretch your arms and hit the wardrobe. It is suffocating right now.

Curtains should be floor to ceiling and get rid of the sheer curtains and buy privacy film windows, that are renter friendly.
The color of the drapes are fine, but something with a sheen or pattern would look lovely too. if you have the radiator on all the time, then blinds or roman shades would ideally be better.

3. your ikea desk is black and everything else is beige or cream coded. if youre ok with the black and beige color palette, I would go with a "glam" style here leaning contemporary.
   large artwork above the desk. Mirror near the wardrobe.

4.your clothes should not be hanging on the back of the door, you either need a good wardrobe system or hooks to hang them preferably out of sight.

5.get a larger lamp, larger rug and ideally get 2 similar or matching nightstands with more heft.

The ikea nightstand is fine, good height for the bed, but it is cramped in the corner and you have 50 percent of the rest of the
room empty.

I can make a little mock for you in a bit, to show you an idea of how your room can look. But realistically you have a great size room and lots of potential so it comes down to what painting/rug you love and who will be using this room for what purpose other than sleep? And the design can go from there.

And, more importantly what is your budget?

Im in England

Thank you. Theres no issue with the wardrobe being beside the bed and i cant move it so id need to keep it there. The curtains will cover the radiator though. the desk and all furniture is very dark brown just looks black from far. and behind the door it should be completely empty? i dont know where else to put those everyday things wardrobe is full. The room is used by just me, also for getting ready, dressed, relaxing/chilling, desk for work/hobbies and getting ready and if i get a piano will use for hobby too. i dont have a set budget like just affordable to mid range definitely for most things, dont want to splurge on anything, the exception is the piano if i get one, so piano-stand and bench, which will be the most expensive.

Maybe a nice abstract or landscape artwork

Yes i want to replace my basic lamp with a nice stylish one with gold on it, around £50-60 max, plus it will match my chair with gold legs.

I do already have a nice brown/mink faux fur throw which i want to use for bed.

It’s really just decor that you’re needing. Look for prints that suit your style and personality. Once you have that then start to coordinate the colors for your bedding and other decor items.
Place the sheep skin over the chair. It’s too small for the floor. For the floor try a faux cow hide throw with your brown mink you could do either a colorful hide or a brown and tan hide.
Are you able to change the window treatment. What’s there now really dates the room, so replace if you can. There are cheap options for draperies and shades.

Since you don't want to spend a lot and keep the wardrobe there, I would suggest to get someone to help you move it to the opposite wall just because it really would be more helpful to have that space.

However if you are absolutely against that then try to leave at least an inch or two from the bed to the wardrobe.

A piano is indeed expensive so I would focus on a beautiful artwork and colorful bedding for the bed and a nice lamp and plants to bring life to the place. Since I am assuming the piano will also be dark or black.

Plants can be placed on the window sill if it Is deep enough, ( would need your measurements)

For the curtains, having blinds or Roman shades , as I said before, would be the way to go. You can keep the curtains pulled to the sides at all times for beauty and warmth to the place.

I found a couple examples of lamps you can use. Since it will be the only lamp, I would go extravagant and gaudy with it so it adds a little character and nice to look at. The animal one is from Lights2go. Other 2 are from Next.

Yes the chair is fine as is, make sure the accent pieces have some gold to lighten the black.

The rug would be nice if it is large enough. For this room, roughly you need a 6x9 or minimum 5x7 to put at the end of the bed. You're in England so it must be somewhat cold there year round?

Art work is really up to you. You need art that makes you happy. Speaks to you etc. Just finding it online mass produced I usually don't recommend But if you can find one that you love, it is always ok to buy cheap online too. You will see it everyday so make sure it has something you adore in it.

Here is the mock also.