It doesn't matter if your Android phone has expandable storage via a microSD card -- you fill up whatever space you're given, whether it's 32GB or 200GB. Here are some easy ways to free up storage on your Android device -- both the internal storage and microSD.
Clear the cache
Many Android apps use stored -- or cached -- data to give you a better user experience. Cached data can save a little time (and mobile data), but the files stored in app caches are for convenience and are not strictly necessary. If you need to clear up space on your phone quickly, the app cache is the first place you should look.
To clear cached data from a single app, go to Settings > Applications > Application Manager and tap on the app you want to modify. In the app's Application info menu, tap Storage and then tap Clear Cache to clear the app's cache.
To clear cached data from all apps, go to Settings > Storage and tap Cached data to clear the caches of all the apps on your phone.
Delete your downloads
Your Android phone has a downloads folder where everything you download -- photos, videos, documents and other files -- is stored. Chances are most of the files in your downloads folder are not files you're particularly attached to. (For some reason my downloads folder is full of pictures of Pizza Hut's Ultimate Hershey's Chocolate Chip Cookies.) So you should be able to free up some storage space by deleting these unnecessary files.
You'll find your downloads folder -- which might be called My Files -- in your app drawer. Tap and hold a file to select it, then tap the trash can icon, the remove button or the delete button to get rid of it.
Take advantage of Google Photos
Guess what? Google Photos lets you back up an unlimited number of photos. In other words, you can back up every single photo you take with your Android phone directly to Google Photos, and it will not count against your Google Drive space. Once your photos are backed up, you can delete them from your device to free up space.
You will need to turn on Google Photos' Back up & sync feature to take advantage of all this free cloud storage space. To do this, open the Google Photos app and go to Settings > Back up & sync and turn it on.
You can choose to back up your photos at "high quality" resolution -- up to 16 megapixels -- or to back them up at the original size. Google Photos only offers unlimited storage for "high quality" photos, and any photos backed up at the original size will count against your Google Drive storage limit.
Once you've backed up your photos using Google Photos, you can go to Settings > Free up device storage, and Google Photos will delete any photos and videos that have been backed up.
Move apps to the microSD card
Apps probably take up most of the storage space on your phone. If you've got an Android phone that lets you add a microSD card for extra storage, you may be able to move some of your storage-sucking apps to that microSD card.
To do this, open Settings and go to Applications > Application manager and tap the app you want to move.
If the app can be moved, you will see a button that says Move to SD card -- tap this button to move the app to the microSD card. (On some phones, you may have to tap Storage to find this option.) Only part of the app will be moved to the microSD card. How much of the app will be moved depends on the app and, unfortunately, many large games will not move a significant portion of their data to the microSD card.
Move apps to the trash
If you've tried all of these tips and you still need more space, there's no getting around it -- you're going to have to start deleting some things. You've probably got some (maybe several) apps on your device that you never use.
To figure out which apps are taking up the most space, open Settings and go to Storage > Apps. You'll see a list of apps sorted by size -- the biggest apps will the at the top of the list.
To delete an app you don't use, tap the app and then tap the "i" icon next to the app's name.
Tap uninstall to get rid of the app.