For Sofia's costume I used the tutorial at Talking Trash and Wasting Time to make this costume and found it to be fairly easy to follow despite never having made a onesie costume before. Of course, now that she has this giant fleecy costume to wear it is supposed to be in the 60s-70s on Halloween!
Henry wanted to be Ash and in order to make his costume I bought a blue shirt from Goodwill and pulled it apart to make it look like Ash's shirt. I basically just had a picture of Ash on the computer and continued to reference it while making the costume. I pulled off the collar and used that as a template for making a larger white collar. I pulled off the long sleeves and used those also as a template, sewed the hem straight, and sewed the button plackets inward. I also bought Henry an Ash Ketchum hat a couple of months ago, knowing what his costume was going to be. I don't count this as part of the costume cost because I know that he will continue to wear the hat after Halloween is over. The hardest part of the costume was trying to find a pair of jeans that I knew existed somewhere in my house (Henry has refused to wear jeans for several years now). But, we found everything and Henry seems happy enough with the results.