I spent a good while looking for this list in the older posts - somehow this info escaped being put in the FAQ. anyway, here is a great list from way back, not sure who originally wrote it, it has been copied and pasted a lot
1) What colors do your birld like/dislike? Any in paticular? If they do like some, try foods of that color, as they will be more willing to check it out sooner. If you know they avoid certain colors (dislike them), don't offer those.
2) Whenever you are home, have veggies in their cage. They need to be changed every 2-3 hours (so they don't spoil), so try to have them in their cage as much as possible.
3) Present the food in diff ways. Offer it in tiny bits, minced, diced, chopped, grated, whole, etc. Some will not touch whole foods, but if you chop it up, they love it!
4) Choose 3 or 4 different foods to offer, and rotate/mix them only; for a few months. This is so he can get used to the look, and hopefully, taste, of them.
5) What is his staple food? Try peeling a banana, cut off an 1 inch section, and scrape off the sides, so it is sticky. Roll it in seeds/pellets, and offer.
6) Try offering seed/pellets for 1 hour in the morning, then only have veggies in the cage during the day. Offer seed/pellets again in the evening for 1 hour. After a few days, they will usually try the new foods. Be sure it is in a food dish (so they know it is suposed to be eaten ).
7) For some birds, all it takes is mixing the chopped up veggies with their regular food, and they will try it .
YOU eat some while theya re out! Say "Mmmm" with big smiles, any enjoyment noise/gesture you have a habit of doing, and offer it to your bird. Eat it outside of the cage while some is with your bird in the cage. Do NOT feed your bird out of your mouth. They have germs that can make you sick, and you have germs that can make the bird sick!
Bad for Them:
anything high in preservatives
sunflower seeds (in large amounts, once and awhile are fine as treats)
most nuts (in large amounts, once and awhile are fine as treats)
sugary foods (not natural sugar (fruits)- added sugar, such as in some of the so called treats at the pet store used to 'glue' the seeds together).