It may sound odd to think that the shape of a vegetable can influence whether or not one wants to eat it, but it actually an important part of presentation. Presentation is HUGE!! Wouldn't you rather eat a beautiful array of assorted veggies in all the colors of the rainbow, instead of a plate of steamed, white cauliflower? Not that there's anything wrong with the latter, but the visual aspect of what one is about to partake in eating is simply a very important factor in whether or not they're attracted to eat it in the first place!
Going with that thought, if you change the shape of your veg, it almost creates a new version of whatever you're used to making. Take squash, for example. If you normally cut it in circles and steam it, try, instead, to use a mandoline with the julienne blades and sautee it with garlic, mushrooms and olive oil. (Incidentally, if you purchase a mandoline, your options increase tremendously with regard to the options of the shapes you can create!)
How about yams? Do you normally wrap them in foil and serve them as you would a baked potato? How about pureeing some baked yams with a touch of olive oil and pepper, and maybe a hint of salt and present them as a whipped starchy veg.
What about broccoli? Do you purchase it with the stalk and end up discarding all but the 'tree' portion? Instead, dice the stalky part up into small pieces and throw it in a cast iron skillet with shallots, garlic, olive oil and some chopped walnuts and let it cook through. About three minutes before serving add the florets, which need MUCH less time to cook than do the thick stalks. Voila- nothing is wasted!
The bottom line is: keep it interesting and varied! Your mind will be more engaged in trying something new if it's healthfully prepared and beautifully presented. It's not just young kids who are picky about certain colors, shapes & textures of foods, so if you keep it as an ongoing, changing and interesting experience to eat new & different preparations of veg, you'll please the whole family!