2 capfuls of vanilla extract in a hot oven for about an hour - makes my house smell beautiful and I look like a domestic goddess.
Genuinely cannot beat the smell - like a lingering bakery but not too extreme/synthetic.
Other than that I use lemon scented cleaning products, it's the only smell that doesn't give me a headache.
Citronella candles for something not too strong but that do a good job deodorising.
I open all windows every day for as long as I can to keep fresh air circulating, always pull back the bed covers so the beds can air out and leave the pillows by the windows.
I do use the fabric conditioner/water/baking powder concoction on my bed; but only with Comfort Pure - smells beautifully clean and fresh but not harsh at all.
Also, rugs and sofa cushions get hauled outside and beaten to remove any smells.
Steam mop tile floors, hoover and dusting daily.
I'm really careful not to use different smells in my house - the synthetic, chemical, mismatched smells are a recipe for disaster.
Lastly, a large sandlewood and sea salt candle that I burn periodically in the living room - another natural smell.