1. Limit widgets and live wallpapers
Widgets and live wallpapers are both pretty greedy when it comes to RAM usage. Many refresh often and occupy bandwidth, while some are continuously active. This can also cause your battery to drain faster. So remember to limit the number of them in effect to optimize your current available memory.
2. Manually close or uninstall apps
If swiping away an app doesn’t help, then you might need to take a tougher approach and close the app manually. This can be done in Settings>Apps, then tap on an app. Under the Memory heading, you can see how much RAM it has used in the past 3 hours.
From there you can Force Stop an app to free up RAM in the short term, or simply uninstall it if you feel it’s not worth using later.