You should know how to use your shield. Raise it by holding down the X (default bindings) key. While your shield is raised, your movement speed is reduced but it absorbs damage from all directions.
A shield can only last a few hits until it breaks. If it breaks, your shield turns into a paperweight and you will not be able to absorb damage until it regenerates. This will take roughly 8 seconds.
To prevent having your shield broken, you have to consider two things:

• The color of the shield barrier (Blue = No damage ; Cyan = Slight damage ; Yellow = Moderate damage ; Orange = Heavy damage. If your shield hits orange, do not try to absorb any more damage as it will cause the shield to break. Recharging the shield from orange to blue only takes a few seconds and it's much quicker than having your shield regenerate from being broken.)
  
• Damage type defense and status resist of your shield

The next section will tell you more about this:

As with armor, every shield has different damage type and status defenses. This is EXTREMELY important to consider as the correct shield will absorb much more damage than other ones might.
As you progress with the missions, you will get a Defender shield. It is quite bad though and you should replace it with a different one. These are the best shields for each damage type:

• For Swordies: ***** Barbarous Thorn Shield (Normal and Piercing protection which protects against Beasts and Slimes, Sword Damage Bonus Medium. To get this shield, run the Gloaming Wildwoods until you have 10 Frumious Fangs. Go to Brinks and trade in these tokens for a Bristling Buckler, then work your way up with this[wiki.spiralknights.com] alchemy path to the Barbarous Thorn Shield. As a Swordie, this is the first shield you should get.)
  
• For everyone else: ***** Ironmight Plate Shield (Normal and Piercing protection, Stun status resist. If you still need protection from Piercing damage and you're not a sword user, go with this shield.)
  
• ***** Crest of Almire (Normal and Shadow protection which protects against Undead and Fiends, Fire and Shock Status resist. To get the Crest of Almire, you first have to complete ~10 Firestorm Citadel (also known as FSC or Vana) runs. Using 30 Almirian Seals, go to Brinks and trade them in for your Blackened Crest. Then, heat it to Level 10, get a Crest of Almire recipe and craft your 5* shield. The Dread Skelly Shield also is an option against Shadow damage, but it will cost more to craft than the Crest of Almire.)
  
• ***** Grey Owlite Shield (Normal and Elemental protection which protects against Gremlins and Constructs, Fire and Shock status resist. However, I do not recommend this shield as you won't have to block a lot of attacks from Gremlins and Constructs. Any other 5* shield does well here. The Firestorm Citadel and the Shadow Lair version of the Ironclaw Munitions Factory are the best places to have this shield on.)
  
• ADVANCED: *** Swiftstrike Buckler (Normal protection, Attack Speed Increased High. With this shield, you sacrifice the ability to absorb a lot of damage for better attack speed. This attack speed increase is extremely useful, much better than damage increase. Only get this shield if you can dodge attacks very well. If you are a gunner, definitely get this as you won't have to absorb anyway most of the time.)

Your shield isn't just for absorbing damage, but for even more important things:

Shield/Animation Cancel
This is the most important thing to be able to do in order to survive.
Let's say, the animation of swinging your Troika sword takes about 800ms. This means that for almost one full second, you will not be able to move and you are vulnerable to enemy attacks. However, with your shield, you can cancel it at about 450ms in and save about one third of a second.
You might even shield bump enemies while canceling, more about this later. Guns, bombs and charge attacks can also be shield canceled. Remember that the last attack of a sword combo and the reload animation of a gun cannot be canceled.
To cancel the attack animation, you either tap the shield key after the animation becomes cancelable, or you hold down the shield key while the animation lasts and release it right after it is canceled. Timing is crucial for both methods.
It is absolutely important to cancel the animation of Flourish-like swords. The first and long range swing can be canceled very early into the animation. A swing-cancel-swing-cancel-swing-cancel combo is recommended.

Shield Charge
To charge attacks with your sword/gun, you hold down your right mouse button. However, it will attack before it gets to charge. To prevent this, hold down your shield key and then hold down the right mouse button. After about half a second, release the shield key but keep holding down the right mouse button. Your weapon will be charged.
This trick is useful in situations where you can't afford to stand still even for a very short time. The Blitz Needle gun will profit from this the most.

Shield Bash
If you raise your shield next to an enemy, they will be pushed away from you. How much it pushes the enemy away depends on your star level of the shield you have equipped at the moment. You can simply tap the shield key to push an enemy away. However, this has a short cooldown, which means that you won't be able to spam the shield bash.
Shield bashing is used to escape from (being trapped by) enemies, pushing enemies inside bombs, pushing Zombies outside a totem's revive range and more. Be careful though, you might end up bashing enemies into your allies, blocking and maybe damaging them.

Congratulations, you now know how to efficiently use your most important survival tool in the game! By combining and perfecting everything that you have learned by reading this guide, your survivability will unarguably increase and death will be something you see only once a while.

Thank you for reading, and rate the guide if it helped you!

These people (IGN) have helped me improve this guide:

• Jakthecat
  
• Fradow