Balloons with photos of memories tied to the bottom is a sentimental and thoughtful proposal idea. Let her pop all of the balloons to find the ring. You can fill the rest of the balloons with sweets, glitter or flowers.
Create an inexpensive and easy centerpiece using food coloring and simple white flowers in bud vases. I like the idea of the colored water with maybe white roses and the colors of the water would be the colors of the wedding