Open your in-game requests manager, find a free gift mask, accept it (send one back if you want) then you will notice a popup in the backround, close out the requests manager, and accept your bonus (Whatever it may be) then repeat the process.
The problem is that if there is already a Bonus popup another won't show up until that one is gone, so if you are accepting several at a time you could be missing out and as many as 40 free masks!! (Maybe more) That really adds up over a several day event! Your talking the difference of an extra item or 2 of the best one!! So get to it and start getting some good loot!!
Click "Play for Masks" and it will give you a one time bonus!
As you can see you are allowed to collect 40 from free gifts and then a total of 30 more from Fighting, Robbing, and Doing Jobs (10 From Each) And it looks like its working from the start this time (Unlike the V-Day Massacre)
So if you follow my steps and work it right you will end up collecting 100+ each day and get some really good loot by the end of the event!