As for trying to save, I've found the best way to save, at least for us, is to learn to make my groceries stretch. We're pretty decent savers, and don't have a lot of extravangances, and those we have I'm not ready to part with for the sake of a vacation. You need to enjoy every day life too! Little things like buying a whole chicken for dinner, then using the bones to make stock for soup for lunch that week, buying meats in bulk (saves us a lot since we buy organic most of the time), and ESP. eating meat free several times a week have really helped tighten our food budget. My husband is a meat and potatoes guy, but I don't think he's even noticed I've done a lot of meat free meals lately.
Also- If you don't get a good enough tax return to pay for the trip, could you get a second job in the meantime? Even something like babysitting or with the holidays coming up (doesn't feel like it, but in retail they will start hiring for seasonal work fairly soon) a part time retail job could help you on your way!
Consignment shops are great too. I didn't really get it until recently, when I had 15 storage containers of my DD's clothes to part with! I found a local group of Moms on FB that had started a group, and I have made great money posting pics of my daughers clothes and selling them. It was time consuming at first, but totally worth it. I brought the rest to the consignment shop down the street from me and made a killing there too. I've made enough that I've bought all my DD's Fall wardrobe with that money, as well as gear and clothes for our son who is due in a few weeks. I'll be selling stuff in the Spring again (and throughout the year on FB), and that money will go towards kids clothes and our vacation.
I hope some of this helps! Don't lose hope, you'll get there!