One of my G2's is very, very picky and the other one, who we just adopted, will eat anything. But the one thing that all our birds absolutely adore is a concoction that I serve every morning. I start with a piece of crumbled birdie bread (you can find the recipe on this site) which is basically a corn bread base with extras. I used crumbled pellets and sweet potatoes, finely chopped veggies, eggs, and whatever else I have available at the time. Then I cook a small amount of oatmeal to which I add about a teaspoon of baby food. Mix it all together and serve. All I see for about 20 minutes is tails in the air.
For the picky G2, I found the best way to get him to try something new is to hang it on a skewer. Then it becomes a toy. The first few times I try something new, he just tears it apart and drops it to the floor of his cage. But eventually, he will actually eat some of it too.
There are lots of threads about this subject. Do some reading in the archives and you'll find a ton of ideas.