Other taking up so much space on my iphone?

I have an iPhone 4s, 16 GB. A while ago i tried taking pictures but my phone wouldn't take in anymore, so I had to fix my storage settings. I fixed my storage settings and took some apps off of backup, deleted some photos and videos, deleted some apps, and then I was able to take in more pictures--obviously, cause I had more space. But my mom and my sisters never had this problem, they have 1000+ pictures (I have almost 500), almost the same amount of songs I have (I have 400), if not more, and they never had the problem to fix their storage. When I plugged in my phone to my computer and saw how much of each was taking up my storage, I saw that my "other" bar was taking up 4GB! I've looked online on what was taking so much space in "other" and never got a definite, clear answer. I've read that's it's normal to have around 1GB, or less. How do I clear off this "other" space?

I'm pretty sure other means alarms, notes, data saved (in games, but probably not), books in iBooks, etc… The not-so app stuff. I'm probably wrong though. But try it and tell me if it relieves some space!