Tips for different workflows/use cases

Hi,

<my_life> Up to recently, I used Git as a frontend to many SVN repo. The workflow is simple: a central SVN and a single "client" desktop. Now, I started to use Git at office. So I "discover" new problems and my actual experience is not enougth. </my_life>

Actually, I discovered two(/three) use cases for which I'm looking the
best (recommended) workflows. My idea is to identify the best
practices to avoid (as possible) complex situations.
1- The same developer uses two repo on two network connected computers.
For any reason, a developer has to work on two computers for the same
project. He sometimes hack on both computers. He uses two git
repositories to keep it work in sync. Note: the two computers are
connected, and the developer can pull/push via ssh.
So, what is the best practices:
- should he decide to push/pull every time from the same repo or
should he only use the "pull" command on each repo (and never push)
- should he decide to create a third repo and use it as central repo.

2- It's a variation of the previous one. Now, one of the two computers is a laptop. Is there any recommended practices to work with laptop?

3- Now, the two computer are not connected via network. Two possible solutions to sync our both computers: USB disk and e-mail. Any recommendation in this context?

I think that such recommendations must be shared on the wiki, for example on GitWorkflows or GitFaq pages.