Make sure you have learnt about your child:
their favourite colour, celebriteies, bands and hobbies. Decorate one wall with whatever colour or pattern/colour they like. Ideally, you should choose one neutral (soft) color, and one bright (bold) accent color. As you go through the steps, sticking with this color scheme, you need to make sure of colours arent mixed those two colours in your colour scheme are th ones you want all around the room which will help all the furniture and ornaments in the room look tied together.
Paint the walls.
Paint is relatively cheap. If you don't want to spend a lot of money on it, though, paint vertical stripes instead.But wallpaper is a really good choice as well so that you have one room that represents you.
Get curtains and a duvet cover.
If you can't find them at a reasonable price, go to the fabric store and sew your own!But you dont need curtains as they are not a must have they are just an extra, sometimes they can even make your room look busy.
The homemaker stores can have some deals so maybe wait till after the chritmas sales.
You could also go to garage sales but the stuff there will mostly be second hand and easily warn or alredy warn. If this happens to you, you can get new covers for them .I would still go to a homemaker centre.
Buy or make pillows.
Get pillows in your colour schemeand throw them on the bed and put them in an orderly fashion for decoration.
Put up shelves.
Build Simple Floating Shelves, on which to put books, candles, stuffed animals, pictures, and trinkets.