I'm studying 9 languages right now apart from the 4 i already know. I spend a few days with slavic languages, move to middle eastern and then to asian. I all depends on what I feel like studying that day. Similar languages like Russian, Bulgarian and even Polish help me reinforce my knowledge in the the other because I can cross-reference the info I learn.
for ex:
Monday
russian - panidyelnik
bulgarian-panedelnik
polish- poniedziaĆek
Don't limit yourself, go above and beyond
for ex:
Monday
russian - panidyelnik
bulgarian-panedelnik
polish- poniedziaĆek
Don't limit yourself, go above and beyond