Clean each room until it gleams. Every window, bit of paintwork, tile. Treat it as if you love it.
Best tip: create focal points in each room. Stand in the doorway and notice where your eyes naturally want to look as you walk into each room. Try to make that area as appealing as possible. For me that is stuff like:
Kitchen windowsill: fresh herbs growing in decorative pots
Dining table: clear, polished with a big bunch of flowers or flowering plant on it.
Sofa - all cushions plumped up and well arranged with a soft throw draped over an arm or the back of the chair. Side table within reach - clean and polished with a beautiful lamp on it, coaster for your mug, a small stack of books you want to read or notebooks if you journal, or framed photos of DC or happy times.
Dresser or sideboard - decorative china or glasses, all polished and well-arranged.
Mantelpiece: clusters of candles, sometimes flowering plants or photographs, a couple of interesting bits of art if they mean something to you. I'd rather have a clunky pot or painting made by DC framed and on display than a generic Live Laugh Love poster.
Bedroom: Clean fresh bedding, soft throw at the base of the bed. No cushions - they only get chucked on the floor when you sleep. Bedside table with warm glow lamp, good book, pretty water glass.
Play around with these focal points and tweak them until you can stand in each doorway in your house, and your eye is drawn to an artfully arranged area that gives you pleasure, invites you to spend time there and means something to you.