You can include other flowers as well, Gigi. Back in January I made this lei from Bougainvillea and a FEW Plumeria flowers (because it was all I had).
Also use leaves as fillers
The wonderful musician and lei artist Kuana Torres Kahele encourages you to make leis from ANYTHING. Here is a gorgeous grass lei....
If you have a facebook page look his up. He shows the most wonderful leis plus he also posts videos with instructions.