Offer a number of choices: Most children will find something interesting if there are numerous choices and the feeling of control in exercising that choice.
 

Focus on natural foods, not processed foods to provide healthy snacks and arrange them in a fun appealing way. Raw nuts, apples, carrots, are all healthy options. Substitute fresh fruit for canned fruit, fresh vegetables for canned vegetables, granola\muesli bars for chocolate bars. Bug organic when possible and check that vegetables and fruits are low on pesticides.
 

Lots of positive reinforcement: Praise healthy snack eaters. Make the healthy snack eaters feel special. Small rewards or sticker charts keep the motivation up and eventually healthy becomes a habit.
 

Be sneaky: Sneak vegetables in to unsuspecting places by adding pureed veggies or fruit to dishes kids love.
 

Be persistent: Don’t expect your methods to work right away but if you hang in there and keep offering healthy choices, eventually they will catch on.
 

Develop substitutes: Raw sugar for white (refined) sugar, whole wheat flour for white flour, and almond butter for the sweeter peanut variety. Make your own home-made chicken nuggets and add some flax to the bread crumbs.
 

Be flexible and allow occasional exceptions if necessary. It is unrealistic to expect all kids to go cold turkey on their junk food, especially when their friends indulge. Specify a limited time during the week when a limited amount of junk foods are allowed. 
 

Offer healthy choices from the start: kids who have only tasted whole wheat bread and not white bread develop a preference for the healthier version.
 

Encourage interest in healthy food and explain the virtues of healthy eating and the costs of unhealthy eating.
 

Be a good role model: You have to start by setting a good example.