How to delete the other in iTunes?

When I get into iTunes and I go to my iphone summary, at the bottom for the "other" it takes up about 3 GB of space on my phone! Even when I look on my phone in the settings my usage space says it's way smaller too. I read where I can use the DiskAid, I tried it, it worked but then a couple days later I plugged it back in again it's back to 3GB! I followed the instructions exactly I had a ton of free space and now I hardly have any! Is there something I did wrong, is there something else I need to do like restore it or should I just not worry about it and just deal with it? Any tips and advise would be appreciated! Thanks!

Added (1). And another thing is when I updated to the new software and it did a backup, would that have caused it to take up so much space and now I can't do much about it? I have the iPhone 5.

"Other" can be anything from settings to system files to data from games and programs. You should not attempt to delete this directly without first knowing what it is. Remove unused programs, trim your videos and pictures, delete read emails. Delete browser cache. You can even go so far as to delete and add back email accounts to clean out read/old messages.

Basically, anything stored on your iDevice that can't fit into one of those 8 categories is categorized as "Other." This includes:

Browser cache
Mail cache
Mail messages
Mail attachments
Safari's Reading List
iTunes Backups
Crud resulting from jailbreaking your iDevice
Game data
Saved data files
Call history
Notes
Media
Voice memos