Video calls. If you aren't having at least one video call a day something is probably wrong. Configure it such that starting a video call takes no more than 4 clicks. Have a company-wide General/Coffee chat where people talk about arbitrary things. It's better if this chat has history which expires in 24 hours. Write lots of short documents -- especially for designs. Review them much like you would review code. This…
Depends on how you work? A video call every day would be too much for me, but two a week seems alright. I'm also not a fan of daily meetings in person either, though.