Cut tulip stems underwater before you put them in a vase and they will last longer.

I always tie them with ribbon , or whatever you like ,near the top under the petals, looks like a hand tied posy and stops them bending over. You'll need a thinner vase.

Put a penny in the bottom of the vase. No clue why this works but it's what a florist told me once.

I bought my mother in law a bunch of tulips recently and she put a drop of bleach in the water before she put them in the vase. I couldn't believe it as I thought it would kill them. It works I've done it twice now, apparently it kills the bacteria.