Reduce special effects
If you are running iOS 7 or, later you might have noticed screen movement. You can reduce these motion related effects
Go to Settings>> General>> Accessibility>> Reduce Motion and turn the toggle on.
Stop background refresh
Background app refresh is one of the multitasking features when enabled lets the apps to fetch content in the background. Most of your apps don't need to be updated all the time.
Go to Settings>> General>> Background App Refresh and disable the functionality.
Spotlight allows you searching a lot of content such as Applications, Contacts, Music, Podcasts, Mails and more, while you might need it only for a few only. Uncheck the apps you don't want to search from:
Settings>> General>> Spotlight Search.
Clear browser cache
Whenever you visit a webpage, Safari will automatically save its content in its memory cache but over time the browser cache fills up to an extent that it can slow down your browsing experience.
In Settings, find Safari on the left side and tap on Clear Cookies and Data on the right site. Affirm by tapping Clear in the popup window.
Turn off notifications
Many apps, when first launched, ask you whether you want them to notify you about important updates and other stuff. After a while you have a ton of apps that want to push notifications and it slows things down.
In Settings, go to Notification and clear out all the apps that you really don’t’ need notifications for.
This information was taken from the following article: