When should I order my invitations?

I think it depends on how/where you are getting them from. If they are custom designed I would ask the designer, but I think if you are going to order one that is premade (and they just add in your info) you could probably wait until like 3-4 months before.
I am working with Tessa on mine already, but they are custom made so it takes a bit longer.

you kind of have to back yourself into a date......think about how much response time you want to give and how long before the wedding you are going to send them out and work from there. I figured in the time I need to put them together and address them and said this sis the drop dead date i need them on.

HTH