Surely you're starting to get the idea. Simply tap into your little boy's fondest interest and have a custom children's bed maker design and build him a big boy bed inspired by that theme and he'll be naturally drawn to it, compelled to leave his crib behind in exchange for this awesome new vision of his fantasies made real.
If you wish, you can keep his bedding the same for a while, to give him the comforting feeling of some sort of continuity in the transition. Or you can have brand new custom bedding designed to match the theme of his big boy bed. Which option is best depends really on the child.
One of the easiest ways to help your little boy have a smooth transition from a crib to a big boy's bed is to give him a bed that he can be excited about moving into (and up to). This is where a custom theme bed can provide great aid. If your little boy may have been emotionally attached to his crib, his feelings could easily change when he sees the alternative - a custom theme bed in the shape of some object of his wildest dreams.
Any content, trademark/s, or other material that might be found on this site that is not this site property remains the copyright of its respective owner/s. In no way does pinupgirlproducts.com claim ownership or responsibility for such items, and you should seek legal consent for any use of such materials from its owner.