I was a little surprised to find out just how many people run into the storage limit issue on their iPhone and either delay or never update to the latest operating system because of this. This seems even more prevalent with iOS 8. Part of the problem is that almost everyone just simply transfers their data from one iPhone to the next (thank you Apple for making that relatively painless). The only problem with this approach is that you carry over all the "cruft" or extra stuff to your new device (on a side node please do not spell cruft with a "k"). So I'm going to give you the really easy way to solve this problem (the "cruft" problem, I'm not touching the issue of "kruft") as well as some pointers for how to better deal with storage issues.
Powering Through an iOS 8 Update
The best way to avoid the storage space issue all together is to plug your iPhone into your computer and download the iOS update through iTunes and install it while connected. The iOS update installation package itself takes up between 4-6 Gb of data, so unless you have that much storage remaining on your device you won't be able to do an "over the air" update". However, once installed iOS only takes up about 1 Gb of storage. If you download the iOS update installation package through iTunes and install it while physically connected to your computer then you don't need to have 4-6 Gb of free space on your device. Most people don't realize this and go through great pains to delete enough off of their iPhones so they update. Don't do that unless you really want to...
Better Managing Your iOS Device Storage
If you would like to do a better job of using the limited storage you have on your iOS device, there are several things you can do to take a few steps in the right direction...
- Delete apps you don't use or rarely use. This may seem obvious, but it is easy to forget that apps can be re-downloaded if later on your decide you need them.
- Connect your device to your computer and download photos and videos from your iOS device to your computer. Once you have done this and ensured that they are safely on your computer and backed up, go ahead and delete the photos and videos from your device. You will be shocked just how much space you are potentially taking up with just photos and vides.
- If you get a lot of photo and video attachments via email or text message, go through through those messages and save off the photos and videos (then make sure you revisit item 2 above) and then delete the photos and videos from your messages.
- Delete music and videos you have synced to your device. A single movie from iTunes can be upwards of 6 Gb. For music, considering using iTunes Match, a $25 a year service from Apple the lets you have access to all of your music in the cloud wherever you go. iTunes Match isn't for everyone, it just depends how you personally listen to music. It does, however, keep you from having to carry around all of your music with you at all times just so you have access to it.