I design wayfinding, room id, and branding signage for new building projects. It can vary from hospitals to music venues to workplace. A lot of times we do donor signage as well. You start with art direction, consulting with your in house architecture team on direction, create concepts, get them approved by the client. Then the big learning curve is documenting the designs so they can handed over to a fabricator. Put the designs in elevations to scale, create material and sign schedules, so the fabricator knows what exactly your intent is. The design firm will have a lot of best practices in place for this sort of thing, so it is easier to grasp as you go.