Oftentimes, lovers desire big gestures because they are missing the small ones. It will take many bouquets of flowers, boxes of chocolates, and thoughtful notes to comprise the cost of a wedding, and in sum, those gestures can be so much more meaningful than the obligatory relationship milestones that everyone trudges through. At the very least, showing that you care will make the conversation about moving the relationship forward more pleasant. When it comes time to talk about getting married or getting a place together or even getting a cat, the discussion shouldn't be about what you owe your girl or how you've come up short in the past. It should be about if you're ready to take the next steps.
As with most of the other items on this list, this is about helping her enjoy the present so that she will be cool if you need a little more time before you dash headlong into the future.