How can I clear my phone storage?

My phone storage has an internal memory capacity of 16 GB and right now it'd completely full. It never used to be this way until just a few months ago. I have only 9 apps installed (besides the ones already installed when getting phone) which is nothing compared to what people have on their iphones. That takes up 6.49GB. I took almost all of my photos off of my phone and put them on my laptop which leaves 5 photos on internal memory which takes up 1.03MB and some miscellaneous files I have take up 0B. So exactly how is all that taking up my whole storage? I presume that cookies and app cache are taking it up, but how do I delete the cookies on my phone? And not to mention some apps don't even have a button to clear cache so I would I do that in apps that don't have that selection. I'm just fed up with not being able to screenshot, watch musical.ly's, update my apps, sync my email or any of that. I just need help on how to clear things, because I don't understand how what I listed in taking up all my storage.

Do a hard reset but youll lose some settings.

We got this MIRACLE of an app last month, called Dr. Cleaner. It is free, and made by Trend Micro - so you know it is safe. We both have 16G iPhone 6 phones, and when we ran this - it's ASTOUNDING! It threw out all the bit and pieces and fragments, and found us about 4G each! We run it ever couple of days now, so the cleaning is not as dramatic- but it never fails us. I think I have 70 apps, and some have quite a but of stored data in them - and I sill have almost 4G of empty space. Get this TODAY! And also see in Setting, when you check storage, where some apps are that are hogs - and see if you can put them on a diet and clean them up a bit. I do not need the train schedule to Madison Square Garden right no w- basketball season is over, and the Knicks ended AWFUL anyway - so thinks like that can go. In the season I need them, I will get them back. Anything you remove is still in iTunes in your computer anyway - so you can get that app back easily, k in the SEASON you need it. But get Dr. Cleaner - I can't say enough good things about it. I told my chiro about it, and while I was getting dressed after a treatment, he downloaded it and ran it - and met me in the hall - STUNNED!

Back up to the Cloud & the delete everthing you don't use.

Mostly junk files. What you need to do is backup the phone and factory reset it. That'll solve the problem for now. You can use app like iMyFone Umate or PhoneClean to clear the unnecessary data. Also turn your phone off once in a while to clear the memory.