While I should disclaim that as a uni student, who lives in a share house most of my home is seemingly poorly decorated (not by personal choice) however, this certainly does not mean that I will let my own personal space go to waste. Without disregarding style or comfort it is quite simple to create a welcoming and relaxing space on a limited budget - all that is required is a little bit of patience.
I say patience simply because it you aim to decor a room in a limited amount of time (not that it cannot be done) you run the risk of a) finding only trend pieces that you inevitably tire of within a matter of months b) waste plenty of money on said trend pieces because at that point in time there was nothing better on offer c) have a thrown together, miss-matched decor scheme that just does not feel right or d) all of the above. Most of my most treasured material possessions have been found when I have not been looking for anything in particular. What I do constantly have in mind however, is an idea of what I want. For me that's a piece that is both designed well and aesthetically pleasing, in a neutral colour tone or natural texture and isn't a kitsch or gimmick item. Think blonde timbers, white marble ascents and a colour scheme that comprises of white, black, brown and a hint of greenery. While I certainly appreciate a minimal aesthetic, I wouldn't categorise my decor choice as being intrinsically minimal - simply due to the fact that I actually have piece that are purely decorative and bare no function at all. That is not to say that I overload my spaces with unnecessary details more so I make a more informed choice in the pieces I will actually enjoy spending most of my time surrounded by. To make it simpler, I've categorised some of my favourite decor pieces in my room currently:
Black Frames - I don't actively look for prints, but when I do find something I can't stop looking at there is no better way to host it than in a classic black frame. Having two of these sitting together can also be quite effective, but bare in mind you don't want to go too over the top in size unless you have the reasonable space. Other alternatives that fit into a minimal inspired space are Country Road's Adler A3 Frame in Natural Wood or using a Paper Clip like this Hay Design Brass Handle Clip to hold smaller prints to the wall.
Plants - Plants are the perfect addition to a room, not only do they make a small space feel more vibrant, if you look for the right ones they can often have beneficial properties for your health. My choices have been succulents as they are so easy to maintain but also Aloe Vera as it is know to assist with sleep patterns. Other easy to maintain plants are Rubber Leaf Plant, Mother-In-Law's Tongue, Boston Fern or even the good ol' faithful Fiddle Leaf Fig (mine have thrived on filtered sunlight and humidity).
Scents - I have a love affair with scents, perfume, candles, diffusers - you name it I have an abundance of. For someone like me who is yet to find a perfume I do not like it can be easy to go over board, my suggestion is find complimentary scents to keep out of boxes on display and if you really can't resist that rosy scent of Diptyque's Baies keep the box and display on rotation with complimentary scents. My current scented favourites are Byredo's Apocalyptic Candle, Diptyque's Figuier Room Spray and Kavaldon's Saint Candle.
Another must for me is a large mirror, not because I desire to be a narcissist. Mirrors reflect light, and by having a full length one in even the smallest of rooms can assist in the natural flow of light. Think of it more as a large light filled frame and less of a narcism trait, there are so many proven benefits to having a light filled room, I know myself that I am far more at ease in a bedroom that is flooded with light - even if that means my neighbours can see everything I own (oh the joys of share house apartment living). My current mirror is from Ikea (similar here) but other interesting alternatives are West Elm's Metal + Wood Floor Mirror or the Modern Mirror by Kmart.
Don't be mislead into thinking that you must spend hundreds to furnish a home, most of my pieces have been found at small stores or even Kmart (hit and miss). The best thing is to have a concept in mind, ensure that no choices are made impulsively - this doesn't mean they can't be bought on the spot but I always aim to be able to at least envision where a piece would fit.