It might even be easier to just take a picture of the Lego man if you are wanting a picture with a subject that doesn't move. The key is to know it will take time and not get frustrated with your child. It took a good number of tries to get him to cooperate. My problem with the invite was getting my son to be still. I am sure you could also use PicMonkey to get some text on your image. I'm certain you could get a cute picture with a regular camera. I have PhotoShop experience and an SLR camera.
I definitely copied her idea because it was cute and cheap. I got my invite idea from Lisa Leonard at this link. I will do my best to gather some great links for you. But if you want to go all out, there is definitely an abundance of ideas. My son is turning 6 and I can bet that he will not remember each detail so I kept my party within theme but on a budget. I am a working mom so I honestly can get overwhelmed when wanting to make it the best party possible, but also finding a balance given my budget and time. There are leads for Lego cakes, lego covers for juice boxes, lego party invites, lego gift bag ideas, lego games, lego decorations, and so much more. As is the case with most things on Pinterest, you can really get into the party and go overboard. I was certain I'd walk in and find Lego balloons and a ton of Lego party supplies. Are you planning a Lego themed birthday party and having a hard time finding ideas? I found all of my ideas on Pinterest rather than any of the party suppply stores, which are incredibly void of anything Lego-related.