Most bulb flowers like cut flower food in the water. Tulips are the exception. They prefer their water straight. Closed tulip buds will open up in the first few days in the vase. They will last a good week or more, with some help.
Temperature is important.
For longest flower life, keep the tulips in a cool spot in the room. Color is the tulip's strong suit. You can create a wild riot of color or try more subtle single color combos such as purple with lavender, light yellow with deeper yellow. Flamed or multi-colored tulips look great mixed with solid color tulips in coordinated shades. This step allows a slimy alkaloid stuff in the narcissi stems to run off.