If you hold E near a dead body and you have a defib on you, you'll automaticly switch to the defib and revive your fallen comrade!
Speaking of reviving, why not give them a little health kit when they get up. People now only get revived with 20% of their health! This is extra important in classic servers like MordorHQ where there is no health regen!
Pressing F5 or F6 in a big boat (?) will switch to the 1st or 2nd jetski on the back, making for a quick escape!
The single-player has three endings, each unlocking either the P90 for the engineer, some random Chinese AR for Assault and the god-like m249 for support!
The SP also has some dogtags you can use in MP. Oh and the Rex revolver after you beat the first mission!
Got premium? You got some battlepacks. Also if you have the digital deluxe or are a Battlefield veteran. Visit the menu in-game by pressing ESC and hit Battlepacks. Otherwise check them on Battlelog.
Want to have a little FPS boost? The BF4settings editor will help you turn on your FPS meter permantly as well as the option to disable DirectX11. A buddy of mine is running the game at 60 fps on medium/high this way. He has a phenom and a 5770!
BF4 Settings Editor
That's all I got, I perhaps forgot a lot, but atleast it's a start. Now it's up to you guys!
http://www.reddit.com/r/Battlefield/comments/1ppian/bf4_the_quick_tips_megathread/