A lot of people may disagree with me, but I'm not a big fan of trying to get children to try different foods. Children have limited food preferences by nature. With my own kids, as long as I knew they were getting a balanced diet (and the way to do that was to serve them that balanced diet in the form of foods they enjoyed and would eat), I didn't care if they tried new foods. I'm not someone who particularly thinks it's important to try new foods if the "old" foods do the nutrition job.
I saw my job as trying to work within the limits of what young children (and my individual children) preferred to eat while they were at that stage when they had such limited food preferences. With two sons and daughter, I found that each child developed more interest in different foods (on their own) at around six (although my sons were more interested in food in general than my daughter was as a child, which is how I was as well).
All three grew up knowing good eating habits. All three grew up trying all kinds of foods (with two of them, as long as those foods aren't meat; because they have, or border of on having, a vegetarian diet).
I've just always figured that because I offered a decent diet, made my kids aware of what is healthy and what isn't; and didn't turn the very personal matter of eating into a power struggle (or my over-stepping my bounds by expecting them to eat what they weren't ready to try), they just naturally grew up to be people who were happy to try different foods but also who pay attention to which foods are healthy and which aren't.
True, it's a little challenging (a lot challenging sometimes) to get a young child to have a well balanced diet, but it can most often be done by knowing which foods offer which nutrients and are liked by the child; and working with that until the child is past the stage of having such limited preferences.