Here's an overview of the map, including helpful call-outs.
This week we'll have a look at how to play the terrorist side on Mirage. The general idea is to take control over one area at a time and limit the number of angles you have to check as you attack the bombsite. I'd suggest that you put in a few extra hours learning grenades on Mirage. To say that grenade management is more important on T-side Mirage than on any other side in the entire game is a bold statement, but one that I'm willing to make. For the same reason I'd say you should think twice about buying if you can't afford smoke grenades. As long as you have a solid plan you'll be able to dictate the course of the round and force the defenders to react to your plays.
It's rarely a good idea to attack the A-site without smokes. My suggestion is to smoke off stairs, jungle/connector and CT-spawn. What these smokes do is that they isolate the bombsite. If the defending players are on the site you can push and go for trade kills and make it a three-versus-three situation where you have planted the bomb and the remaining CTs will have to fight you as well as the clock.
Here are the smokes compiled into a single gif:
I usually have one player below T-ramp protecting his teammates while they throw the smokes and one player in palace, whose job it is to use utility grenades to help his team with the push. If he's not smoked off he can bounce a flashbang on the wall so that it bounces past balcony and flashes any potential threat hiding in shadows.
If he is smoked off, on the other hand, he has another option. He can either use the flash mentioned above or he can throw a molotov down to shadows and force any player there to move out in the open to a disadvantageous position.
Once you have the site your number one priority is to protect your bomb carrier. Pre fire the box next to ticket booth and use flashes. Do whatever it takes. Just don't let the CTs stop him from planting as that'll give rotating players more time to get in position for the retake.
You can also have a guy lurking in mid or underpass, ready to kill any counter-terrorists trying to rotate through connector.
On the next page: controlling mid and managing your eco rounds.