Adjacent doors hitting each other
Another solution: Make one of them close to avoid clashing.

I reversed my kitchen door so it opens into the hallway instead of into the room.  That means it can clash with the cloakroom door if that's left half open.  I solved it by fitting a (very gentle, in fact modified with a weaker spring) automatic closer to the cloakroom door, so it doesn't stop half open.  

Rehanging a door can be tricky but is perfectly doable with reasonable DIY skills.  It's one of the simplest tasks for which you need a decent set of chisels (in fact it's the main reason I even have chisels).  The job needs proper planning: when I did mine there was enough space on the new side of the frame to make it simple but had it been on a different (non-structural) wall it would have been much harder.