We like a colourful, eclectic style and most of our furniture etc is from eBay/auction houses while a few things are from favourite local - and not so local - antique dealers .
I'd say we've always been maximalists but the eclectic vibe we have now has evolved over the years - when I met my DH as a student, I collected art deco stuff from fleamarkets/carboots (the cheapest as it was all I could afford) and that naturally progressed into art nouveau/arts and crafts movement pieces. This culminated in a fairly large collection (mostly found on eBay during the early noughties) which suited the Arts and Crafts style house we had then. Back then people we knew assumed everything had been picked up for peanuts as that's what they associated ebay with - actually our most expensive buy was a £4k sideboard!
When we decided to sell that house we gradually sold off our collection - which included ornamental and textile bits too - and our look evolved again into a more eclectic style which now incorporates a few mid century and more contemporary items.
So we now have four sofas all from ebay - one was bought new, one is antique and the other two merely preloved!
Other furniture including a massive Victorian larder cupboard and chest of drawers also come from eBay, Art Nouveau bookcases are from various auction houses across the UK. I love seeking out interesting, quality pieces that have a story to tell, although for practical reasons we did succumb to a large bank of ikea Besta cupboards in the hall.
We have added period features (eg, fireplaces) to our old-but-stripped-out house and have found many of these architectural pieces at fleamarkets and auctions.
Art is a mix of antique fair finds, framed prints and stuff I've painted myself. Mirrors (we sold many but still have loads) are again mostly from eBay.
My big love is textiles and in order to get as many wonderful fabrics into our home as possible I search out interesting examples and make cushions etc as these are - relatively - cheap to make and small too.