A bow at the waist adds flair to a simple ensemble. Wear it oversize or understated; in the centre or off to one side; a sash, a ribbon, or a chic bow belt like Casey's, above right (she's even posted a great tutorial to make your own).
Left: Schiaparelli's 1927 bow knot trompe l'oeil sweater was shocking and innovative. If you're a knitter you can download instructions to make your own, otherwise there are many lookalike options available on sites like etsy and ebay. Right: Bow-trimmed sweater shot by Nina Leen in 1952 - get the look easily by pinning little ribbon bows to the front of a plain sweater.
In kitsch plastic or sophisticated Art Deco marcasite, some of my favourite brooches have a bow motif - they're so easy to wear because they go with anything.
Fabric bows accent the corners of a sweetheart neckline. I absolutely love this look for its girlish charm - a sweetheart neckline dress is on my (long) to-make list.
Embroidered or applique, or even sequinned! This sequin bow neckline ornamentation has been in my sewing inspiration folder for the longest time - one day I'll make one for myself!
A huge bow adds real va-va-voom to a cocktail or evening ensemble, or a bit of glamour to daywear. Left: surely one of the most iconic film costumes of all time, Marilyn's "Diamonds Are A Girl's Best Friend" pink dress from Gentlemen Prefer Blondes featured an enormous bow on the back. Centre: In the early-mid 1930s there was a vogue for oversize bows at the neckline. Right: The draped hip bow on this 1940s dress offers a different, slightly more subtle effect.