When using VSS on a laptop, before you leave the office, check out any files you think you might want to change.
If multiple checkouts are enabled, feel free to check out all the project files. You can undo check out later on those you didn’t need. If multiple checkouts is NOT enabled, then only check out those files you think you will need.
Checking out binary files will prevent anyone else from checking them out, so use discretion when doing this.