what kind of flowers go with a blush princess dress?

For a classical timeless look you can compliment the dress with a full round posy bouquet of Peonies or David Austin roses in cream and blush pink.

For a traditional bride who wants more flare, a trailing bouquet with soft blooms like Dahlias, David Austin roses, and Cymbidium orchids and Singapore Orchids will leave a lasting impression in cream and/or blush pink.

However, if you're after a jaw dropping effect, an ombré bouquet of cream, pale pink, baby pink to hot pink in soft blooms mentioned above, will definitely get your guests talking for years to come!

I would recommend soft pastel colours, pale pink and white, with either green foliage or silvery grey dusty miller. The exact flowers depends on the time of year for your wedding, ranging from peonies to dahlias as main flowers. Of course roses are available year round, and the bouquet could be complimented by pale pink hypericum berries, floaty Veronica or astilbe.

White and blush roses  and also flowers that are in season depending on time of year of wedding.

Just white flowers would look great as well with a bit of greenery.

A small tear drop style bouquet in Phelenopsis orchids in white would be lovely. Or You could opt for a gorgeous gathered look bouquet in shades of cream and pale pink including things like ranuculas, Peony, Roses, grey foliages etc anything  soft and pretty. Blush pink is a gorgeous colour to work with.  

I'm guessing it's your wedding gown?  Flowers to compliment your blush Princess dress include garden spray roses,  lisianthus, dahlias, roses, Blushing Bride (if it's a winter wedding) and lots more....

It would be nice to have a mixture of blush roses and ivory blooms done in a traditional round bouquet in my opinion to go with this kind of dress. The roses would be available all year and the other flowers available would depend on your wedding date.