Is it maybe less you want to make it look like a cottage and more you want that chocolate box pretty warm welcoming home look?
Things like a wooden trellis arch at the front door, with a trailing plant over it. Or two large trees in beautiful pots either side of the door, with battery operated fairy lights, I have olive trees.
Lots and lots of pots outside, plants, flowers, small trees, make the pots good ones, they make all the difference. For example I love the heritage garden pottery ones. Expensive but they will last forever.
Inside ..rugs, throws on the sofas, pictures on the walls, nice muted colours on the walls,, tall plants in the corners of rooms with fairy lights round them, soft lighting, interesting and good furniture you love.
Same for accessories, always buy only what you love. Not generic crap from Homebase or something, spend time looking on line.you can get things like curtains, blinds, cushions, lamp shades, made for you by people on Etsy for reasonable prices. Look at some of the art shops on line, you can have an unusual print of your choice framed to your specifications for less than a generic print in next.
Look at the artists shops on Etsy, again you can buy beautiful originals from little known artists quite cheaply.
There is lots you can do, but the one rule I've learned, is don't buy something just to fill a space. Wait, spend time looking, think about it, and find something you love. Even if you have to save for it. Even if it takes a year to find it, Because you'll have it for years and love it for years. Don't buy for the sake of it, buy it because you love it.
Someone said to me "it's not just your house that's beautiful, it's everything in it" Which is a huge compliment, but it's not because I spend a lot of money, but because at the grand old age of 49 and having lived with my husband since I was 23 and coming to the realisation the man thinks everything should last forever, I only buy what I love.
For example I've a huge coffee table, I want something for the centre of it to replace what's temporarily there, I've been looking for several months on and off, and I haven't found it so I haven't bought it.
So take time over it. Find the things you love one by one. Things you think are beautiful, the you absolutely love. Then buy it. Over time your house will become a much loved home. Structural changes do make a huge difference but filling it with things you love inside and out, it will take on rhe look and feel you want.