I love to use low priced flowers from the Farmer's Market or Trader Joe's. If time permits, I sometimes drive downtown to hit up the LA Flower Market... (again lets call a spade a spade, I've been twice... time never permits but it's still a really great place to get gorgeous flowers on the cheap). In this case, I picked up a dozen roses for $6 at the Farmer's Market and Trader Joe's had this pack of 3 Hydrangeas for $4.99.
Start with your big blooms. Be careful not to cut the stems too short, start long and keep trimming down until they are the height you want. The oasis will hold the flowers in place once you stick the stem into it. Tip: Flowers with big blooms like these hydrangeas, peonies, or sunflowers are easy to work with - just a few of them will fill a lot of space. I feel like I could have stopped here with an all white hydrangea arrangement.
Then start filling any holes with the smaller rose blooms. Be sure to continuously rotate the container so that one side is not heavier with flowers than another. It has to look good from all angles if it's going to be a dining table centerpiece!
Here's a view from the top...
And a shot of the whole tablescape.
Not bad for $11 spent!