We pretty much always try to alter something we already have before getting something new.
Ds is using my day bed from high school for now and it will be dd's later, he also uses dh's old dresser.
When we cleaned out our office to make dd's room and got rid of years of old paperwork, we put an empty filing cabinet in the coat closet to hold items like hats, scarves and gloves and an extra set of shelves in ds's room to organize games.
We used a kitchen storage unit with a countertop as a desk for awhile, it was small and fit in the corner of our room. Now we just use a few shelves we already had to store office stuff.
I have an old school desk from 1906 I use as a lamp table in my living room.
We have extra wood from the back fence that was recently built and dh is going to build a bench and a balance beam for the backyard.
Dh also took an old basketball hoop from school and made a backboard and pole for it and installed it in the backyard.
Just last weekend, I found a nice looking curtain panel on super clearance at Target and made three valances from it: two for the dining room and one for the kitchen. I also took a small table cloth I had and made a valance for our room.
Dh rescued a bike trailer from the recycling at school that had worn out fabric sides and made new side panels for it, we used it for years with both kids.