If you don't use 'Google Now', I suggest you should. It will make your life much easier. It's easy to use just say "OK Google" and speak whatever you want. Try experimenting with different phrasing, you’ll be surprised how much it understands. Below are some common and important commands which can be of help.
How old is [Name]?
Where was [Name] born?
What time is it in [Toronto]?
Search for [photography tips]
Show me pictures of [Eiffel Tower]
Do I need an umbrella today? What’s the weather like? What’s the weather in [Place] [this weekend]?
What the [Google] stock price? What is [Apple] trading at?
What’s [220 yards] in [miles]?
What’s  divided by [7.5]? (This is amazing many maths equations work)
Search [Tumblr] for [dog pictures]
Take a picture/photo
Record a video
Launch [Chrome] Turn on/off (Bluetooth, Wi-Fi, Flashlight)
What’s the tip for [250 dollars]?
Set an alarm for [4:30 am] Set a timer for [30 minutes]
Create a calendar event (meeting someone/place/time)
Remind me to (buy thing/place)
What is my schedule for tomorrow?
Make a note: [anything] Find [anything] (Works with all info in your contacts - addresses, birthdays, etc.)
Show me my last messages.
Call [Name] Call [Name] on speakerphone
Text [Name] [Your text] Send email to [Name], subject, [whatever subject], [message] Post to [Twitter]: [post] What is French for [This is ridiculous]?
Send a [Hangout] message to [Name] also works with WhatsApp, Viber, WeChat,NextPlus etc)
Navigation and Travel
Where is the nearest [Chinese restaurant]?
Directions to [Place Name] by [car/bike] Where is [the place name]?
Call [Fitness Center] Where’s my hotel?
What are some attractions around here?
How do you say [good night] in [Chinese]?
What is [50,00 Euro's] in [dollars]?
What’s the flight status of [name] flight [number]?
Show me restaurants near my hotel -or- Give me directions back to my hotel.
Play [whatever game you want to] Play some music (Next Song / Pause Song)
Play [Happy] (songs must be in Google Play Music on your device)
Watch [A few good men] (movies and TV must be in your Google Play account)
Read [Hunger Games] Did the [Giants] win today? What’s the score in the [Warriors] game?
What movies are playing [tonight]? Where is [Movie Name] playing?
Say a team name to get the latest score during the season.
When is the next [name] game?
Where are the [Team] in the [league] standings?
Who does [player name] play for?
Who won [the Superbowl]?
When is the [Euro Cup final]?