While all of us love getting new devices sometimes that's not an option. Whether it's lack of funds or trying to hold out until the new device you want releases. During those times using an old device that feels slow and sluggish can be a huge bummer! For my tip I thought I would share what I did on my older Nexus 7 tablet to help hold me over until a new tablet releases.
First you'll need to enable developer options. If you do not already have these enabled or know how to go to Settings>About>Software>Build Number. Tap your build number a few times in a row and you will see a prompt saying that you are a developer.
Once you have this enabled go into your developer options and scroll down to Transition animation scale. By default this is set a 1x change this to 0.5x. Your apps and pages will take less time to load through the animations the device uses and will help the device feel snappy again.
I hope this helps someone out there that's struggling with an aging and slow device! Let me know how it works for you or if you have any other tips that will help make old devices feel new again!