Git Workflow: Without a server

Question

git is supposed to be a decentralized system, but all the tutorials and best practice workflows I have found on google suggest using a server (usually github, or else set up your own)

I am using git for small personal projects (2-3 people), where can I find a best practice workflow for syncing changes directly between the team members machines. Alternatively, what are some compelling arguments for why I should avoid this and instead set up a 'central' server?

Thanks,
Ben