I will resist the temptation to suggest light and bright and pops of colour that are so frequently offered. In this case hearing you wanted modern, but also reading between he lines, and presuming you want a somewhat sophisticated but also moody bedroom, which is modern and stylish without being fussy. Brown is a neutral best used to effect with tonal variations. Anything from lighter coffee tones to rich deep chocolates and even charcoals will bring out the structural bones of the room.
Textile will soften the harshness of a dramatic darker space, layers add luxury and comfort to the bed, so it's where I would spend my money.
In a small bedroom, or any bedroom there is a style essential checklist, which would read like this.
The largest bed suite you can accommodate, a queen as a minimum for a master.
Beside table, shelves, chests or drawers typically one per side, lighting for either side, either pendant or Soft ambient lighting, an armchair, this has the ability to create the style mood, set the scene if you like and will surprise you how often you use it, and lastly artwork.
I'd go a large single piece opposite your bed, so you see it, but you an also use link in pieces either side of your bed, or a gallery wall above your bedhead, it all depends on your style.
Build layers with texture, many fabrics in throws, pillows, cushions and drapery, then continue with accent pieces in lighting, candles, a planter or a candle. Even for a guy, these things are what will complete the look, making it a spae you'll want to retreat to, and then never leave!
One last tip, try not to use too many colours on permanent areas such as walls, Instead opt to use caramels, or grey stone colours and introduce colour in art for personality or less permanent accent pieces than can afford being changed, neutral colour even bold rich colour on the wall to set the mood, it will provide a rich backdrop for dramatic art and blend into your carpets. As for drapery, I'd go similar to your carpet so it feels unified and consistent, even if you have a blackout blind, don't avoid dressing the window,it makes the difference between any bedroom you've ever seen in hotels or magazines you aspire to, and what peopl actually do. Usually very differentpeople settle on practical and don't bother to go beyond that, that is where the first mistake is made and the difference from designers and diyers.
Good luck

Megan, i read your posts and want to hug you. i'm not at this stage yet, but have book marked for when I am.

Good thing about starting with a small space,is anyone who has the luxury if a bigger room or even a suite, can add more furniture prices or be bolder with their choices.

For right now, opt for plain linens and patterned accents rather than printed or patterned quilts, as they will date quicker and dictate the rooms style. Quality spends on generous even oversized bedding is paramount to a bedrooms success in eery sense! Designer pieces. Come and go, so change it up each season injecting enthusiasms all year round.
This sounds somewhat subliminal, but I promise, I'm talking about the interior. :)

Seagrass wall paper...trust me!