TLDR

One of the big draws with using an Android device is that it is very easy to customise it to your liking without even having to jailbreak/root the device. Nova Launcher Prime allows you to tie gestures on your home screen to a selection of predefined actions.

The 3 that I use the most are:

Quick Search: the ability to swipe up anywhere on my home screen to quickly search Google (like Google Now but faster).
Pull Down Notifications: with a large screen phone it can be a mission getting to notifications and toggles with one hand as you have to pull down from the top of the screen. This mod remedies the problem by allowing you to easily use one hand to get to the notification and settings panel, by swiping down anywhere on the home screen.
Quickly Find an App: As of the writing of this article I have close to 200 apps on my phone. Even with less apps, perusing through the app draw or organising apps yourself can be a time consuming process. I have found that the fastest and most efficient way to get around this is by using a double tap gesture on the home screen to bring up the app search box and only type the first few letters of the app's name to find and run the app.

The Nity Gritty

To configure these features you will need to install the Nova Launcher Prime app.

This is one of the few apps I paid for and I found it very worthwhile to do so, simply because of these 3 gestures alone. There is a free version of the app but to use the tips mentioned below you'll need the paid version as that unlocks gestures.

The app will replace your home screen and allow you to enable a number of tweaks.

Quick search

You may think that Google Now should provide this feature. It does to some extent expect for the fact that there are too many steps involved when searching. For the typical Google Now search you need to:

Pull up the home button to activate Now
Move your finger all the way to the top of the screen and touch the search box
Wait for the keyboard to show up
Input your search query and search

That's 2 additional unnecessary steps (why would I need to touch the search box first to get the keyboard to show ?!) On the other hand with this gesture all you have to do is:

Swipe up anywhere on the home screen to bring up the search portion of Google Now with the keyboard ready to accept your search term.
Input your search query and search.

Nova allows you to choose from a number of different gestures and tie a selection of actions to them. For this search action I settled on the "Swipe up" gesture as it aligns with the Google Now gesture of swiping your home button up. To enable this:

Open Nova's settings
Look for the "Gestures & inputs" setting
Scroll down to where it says "Gestures"
Tap "Swipe up"
Choose "Search"

Pull-down Notifications

Getting to notifications on some of these newer large screen phones is generally a two handed effort or for those attempting it one-handed, it can be quite precarious and the cause of dropped phones (you need to grip the phone, angle your hand in a strange way, reach for the very top of the phone's screen with a finger and pull down).

Apple has really designed their notification panel well in this respect as you need only pull up from the bottom of the phone which is much easier on a big screen device using one hand.

To get around this issue on Android a Nova gesture can be set up which allows you to pull down anywhere on the home screen to see notifications and toggles, which is trivial to do with one hand.

The steps are basically the same as with the search gesture but with a different gesture and action chosen:

Open the Nova settings
Look for the "Gestures & inputs" setting
Scroll down to where it says "Gestures"
Tap "Swipe down"
Choose "Expand Notifications"

Quickly find an App

The current setup on phones is laughable you either need to trawl through your app draw to find the app you want or sort apps into folders to more easily find them in future. This is analogous to the early search engines (pre-Google) where people went and tried to organise websites into categories (think early Yahoo!).

This mod allows you to search for an app by double tapping anywhere on the home screen, typing in the first few letters of the app's name and then choosing the app from a grid of possible matches. Apps where the app name is made up of multiple words (like Amazon Kindle for example) will also be found if you start typing letters for any of the words making up the name.

With this you can also perform other actions on apps other than just opening them. If you long press an app you've found you can:

Uninstall it
Get information about it
Edit it
Move it to your home screen

The edit option is really cool, it allows you to categorise your app into one or more groups. If you now search for the group name the app and any other apps in that group will show up. For example if I place a game in the games group and search for "game" all apps that are in the games group will show up even if the word "game" is not in their name as with Clash of Clans or Boom Beach in the screenshot below.

This like the previous steps is configured in the Nova Settings:

Open the Nova settings
Look for the "Gestures & inputs" setting
Scroll down to where it says "Gestures"
Tap "Double tap"
Choose "App search"