There are numerous things you can do. I always suggest when asked this question, decide what you can afford to spend, write down that amount and then decide how big of a project you have planned and then decide what might be feasible with the allotted amount you have set aside.
Here are a few suggestions, use things you already own and re-purpose them, painting them, recovering, reupholstering, and also I suggest bartering for things you might need. Trade with friends and family members items you need to complete your project with items they might want of yours. This way you get a new look without using up your budget money and they get a new look too. You both win!!
Their sofa might look great in your home and vise-versa.
It's amazing the things you can do if you put on your thinking hat, all kinds of ideas can come forward.
I also suggest when you are working on a project and you hit a dead end, recruit a friend or family member for ideas, they might come up with a suggestion you would never have thought of without them.
I hope these suggestions help and remember to just stay passionate and your dreams of decorating will come true.