My fiance and I created our own invitations from scratch. We ordered square pocketfolds, envelopes, and RSVP envelopes online, and we purchased cardstock and vellum for the inserts.
We used Adobe InDesign to design the text and inserts. Our monogram is printed on the white cardstock we adhered to the pocketfold, and the invitation text is printed on vellum and secured over the white cardstock.
We measured and cut each of the inserts to fit in the pocket. My finace created the map using InDesign as well. We assembled all the invitations and added handwritten names to the outside of each pocketfold.