The default scheme with the common home directory across distros works fine. except for some side effects on the desktop. Since desktop (KDE. GNOME. Xfce .... ) versions vary across distros. you might get widget load errors and some unintended desktop icons while hopping from one distro to another. This is because the 'dot' files for your desktop are common across all distros. There is also the possibility of opening a file with a newer version of a software in one distro and rendering it unreadable by the same software with a different version number from another distro. As a solution. the following two approaches have worked for me. singly or in combination.

Rather than mount a common /home. you can let the home directory stay with the respective distro so that your desktop stays there as well. Each distro then gets its own desktop and there are no unpleasant side effects. You can then mount your previously designated home partition separately under. say. /mnt/home. If you like this approach. provision adequate space for the root ("I") partition of each distro (so that a 'small' /home directory can stay there) and do not give any partition as a mount point for /home while installing. This way the /home directory gets created in the root partition of the distro. automatically.

The second approach is to follow some discipline. It helps to have a main distribution that you will use for mail review and other daily chores. You would rather not be messing around with mailboxes across distros. Having voted for your main distribution. you can then boot the distribution that specialises in the task at hand: perhaps media editing or gaming. With this approach. specific file and data types stay associated with a specific distribution and sanity can prevail all round, Your mileage will vary depending on the distros you multi-boot. You should experiment to arrive at the template that works best for you and the work discipline that goes with it.