Unlock the following decorations by performing the corresponding tasks:

DECORATION - HOW TO UNLOCK
Bullz Eye - Get 100% accuracy.
Hawks Eye - Get all intels.
Iron Man - Do not get hit during the mission.
Predator - Engage all fights.
Team ELITE decoration - No teammates hit and 50% of enemies dead.

Unlock the following decorations by performing the corresponding tasks:

DECORATION - HOW TO UNLOCK
Act 1 (elevated risk) decoration - Complete act 1 under elevated risk.
Act 1 (low risk) decoration - Complete act 1 under low risk, normal risk, or elevated risk.
Act 1 (normal risk) decoration - Complete act 1 under normal risk or elevated risk.
Act 2 (elevated risk) decoration - Complete act 2 under elevated risk.
Act 2 (low risk) decoration - Complete act 2 under low risk, normal risk, or elevated risk.
Act 2 (normal risk) decoration - Complete act 2 under normal risk or elevated risk.
Act 3 (elevated risk) decoration - Complete act 3 under elevated risk.
Act 3 (low risk) decoration - Complete act 3 under low risk, normal risk, or elevated risk.
Act 3 (normal risk) decoration - Complete act 3 under normal risk or elevated risk.
Master Tutorial Challenge 1 - Kill all of the enemies without getting hit.
Master Tutorial Challenge 2 - Kill all the enemies with one headshot per enemy.
Master Tutorial Challenge 3 - Kill the tank using only one satchel charge.
Master Tutorial Challenge 4 - Have your team kill all five enemies.
Mission Accomplished Decoration - Complete all secondary objectives.
Single Player Master Decoration - Unlock all other single player decorations.
Tutorial Walkthrough Decoration    - Complete the tutorial.

Unlock the following headgear by having a saved game file of the corresponding games on the PS3 hard drive:

HEADGEAR - HOW TO UNLOCK
ICS-PL Helmet - Rainbow Six Vegas saved game file.
J-E FO Helmet - Splinter Cell Double Agent saved game file.
PAS GT Helmet - Rainbow Six Vegas saved game file.
Tactical Shemagh - Splinter Cell Double Agent saved game file.

Unlock the following music videos by completing the corresponding missions:

MUSIC VIDEO - MISSION
Gimme Danger - Mission 1
Battle Axe - Mission 3
Hero - Mission 7

To unlock character info, you must unlock 5 decorations. To unlock weapons info you must unlock 10 decorations.

To unlock all weapons, complete the game.

Use the drone to recon areas before you enter them to prevent fighting large amounts of enemies.