Running out of storage space to install new apps used to be a real problem for Android phones, particularly budget devices that may have come with only 4- or 8GB of storage built-in.

These days Android phones have larger storage capacities as standard, but if you get a bit too trigger-happy with the camera or run away with yourself in the Google Play store it's still reasonably easy to run low on storage.

Even if you've deleted everything you can think of, though, one problem with low-storage Android devices is that the operating system can often get clogged up with cached files.

As a result Android might refuse to let you install new apps and report an "insufficient storage available" error message.

This is often seen after you have transferred a large amount of data from the internal storage to an SD card, and the cache has not been properly erased. 

This is infuriating when you know there should be enough storage space on the device to install the app, but first you'll need to clear up some junk files and empty Android's cache.

We'll explain how to make more space on Android and fix that error message in our step-by-step guide.

Uninstall unwanted apps

With so many free apps to choose from in the Google Play store, people will often download an app without a second thought. If it doesn't do what they want or they don't use it very often, it's easy for that app to get forgotten about.

This is because, unlike iOS, most Android phones have an app tray that can contain multiple pages. If that unwanted app isn't staring at you on the home screen, and you aren't prompted to download any updates for it because updates are set to automatically download over Wi-Fi, you probably won't even know it's there. 

Open the Settings menu, select Apps, then go through the list looking for any you no longer need. If you find one, select it, then choose Uninstall.

You can also usually uninstall apps from the home screen or app drawer. Just tap and hold on an app and drag it toward the top of the screen; an Uninstall icon should pop up and you just drag the shortcut on top of this and agree to uninstall the app.

Remove photos and videos from device storage

You probably have a load of duplicate or unwanted photos and video in your image gallery, and these can take up a huge amount of space. You have two options here:

1. Go through the Gallery app and delete anything you don't want

2. Download and install Google Photos, use it to back up all your photos and video to Google's servers, then delete the media from your phone's storage. (You may need to follow step one before you have enough space on your device to install the app.)

We recommend following both these steps actually, since it will provide you with a backup of all your multimedia should you ever lose or break your phone.

These photos can also be accessed from any device to which you are logged into your Google account, which will ease moving to a new phone and taking your stuff with you.

Clear out your Downloads folder

Every time you download a PDF or other document from the web - think credit card statements and restaurant menus, for example - that file is stored in your downloads folder. If you no longer need the files, delete them.

You may have a File Manager app preinstalled on your device; if not, there are many free options on Google Play. Simply browse to your Downloads folder and select and delete anything you don't need.

While you're there, if you're using WhatsApp also check your WhatsApp > Media > Images > Sent folder. There is probably a fair amount of stuff in here you don't need. 

Empty Android's cached files

If you've cleared out all the files you don't need and you're still receiving the "insufficient storage available" error message and don't really know why, you need to clear out Android's cache.

On most Android phones this is as simple as opening the Settings menu, browsing to the Storage menu, tapping on Cached data and selecting OK to the pop-up when it prompts you to clear cached data.

You can also manually clear the app cache for individual apps by going to Settings, Apps, selecting an app and choosing Clear Cache.

(If you are running Android Marshmallow, go to Settings, Apps, select an app, tap Storage and then choose Clear Cache.)

If this doesn't work for you, there is a free app you can download (presuming you now have enough space) that can do this for you. We'll explain how on the next slide.

Automate the process with App Cache Cleaner

A free app called App Cache Cleaner – 1Tap Clean can automate clearing out junk files for you. Search for it in Google Play, then when you've found it select Install and agree to the Permissions. Open the app once the download completes.

This app couldn't be simpler to use: just click the huge Start button on the home screen. App Cache Cleaner will then inspect your phone and show you the current burden of each of your apps on the cache.

Either hit Clear All at the bottom of the screen or go through one by one deleting the app caches. You may prefer not to delete the cache for certain apps, since cached files can speed up operation of that app.

While you've got the app open, also select the Junk Files tab and clear out anything you find there.

Follow Marie Black on Twitter.