First of all, don't fall into the "hide the veggies in snack food" trap. If you want to teach your child to eat properly, they have to SEE what they're eating.
One thing I can recommend is, be consistant and remain firm. Another is, it's OK to compromise on some things. For instance, my daughters (5 and 3) will eat almost anything - including veggies - but don't like pork. When I serve pork with, say, rice and asparagus, I give them the rice & asparagus, but will give them chicken nuggets. As long as they get their veggies, grain and meat, I'm OK.
Another (and this one worked great with my 3-year-old, who isn't actually going to be 3 until Thursday) is...no dessert or any after-dinner snacks unless they eat an acceptable amount of actual dinner.
Lastly, occasionally serve a dinner that you know she likes, but YOU eat it, too! My girls love it when I make chicken nuggets & french fries, or mac'n'cheese, for the whole family.
Incidentally, we have always eaten dinner as a family. I don't tend to serve the girls one thing and myself & my husband something completely different (with the exception of the above mentioned examples).
Remember, the MOST important one is "consistant and firm". YOU are the parent. A few battles now will relieve you of a bunch of worse battles later.